Parallel Sessions Chairs (preliminary list)
 
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Georgy ALEKSEEV Parallel Session: ES1 - Exact Solutions in Four and Higher Dimensions: Mathematical Aspects Description: This Parallel Session will be devoted to a variety of mathematical methods, associated mathematical structures and other mathematical aspects of the analysis of Einstein's field equations, constructing exact solutions and development of various solution generating techniques, interrelations of different approaches, classifications of solutions, studies of the structures and geometrical properties of particular solutions and classes of solutions in General Relativity as well as in various gravity, string gravity and supergravity models in four and higher dimensions. |
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Lorenzo AMATI Parallel Session: GB3 - Cosmology and multi-messenger astrophysics through Gamma-Ray Bursts Description: Parallel Session: HE7 - Future missions for high-energy astrophysics Description: The detection and study of high-energy photons from cosmic sources and phenomena has been revolutioning modern astrophysics since the '60s, providing unique clues to, e.g., the existence and properties of black-holes and neutron stars, hot gas and dynamics in galaxy clusters, non-thermal emission processes, engine and extrem physics of active galactic nuclei, shock-emission in pulsar-winf nebula and supernova remnant, as well as the discovery of peculiar and mysterious phenomena like Gamma-Ray Bursts. With the very recent birth of multi-messenger astrophysics, high-energy astorphysics is going to play an even stronger role in astrophysics and cosmology. This session is focused on the description of the many X-/Gamma-ray astrophysics space missions and experiments currently under development or at the proposal / study stage worldwide, that will provide a substantial contribution to the advancement of modern science in the next two decades. |
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Giovanni AMELINO-CAMELIA Parallel Session: QG2 - Quantum Gravity Phenomenology Description: Talks presented in this session will focus on the possibility of finding experimental manifestations of effects introduced at the Planck scale, relevant for the study of the quantum-gravity problem. |
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Luca AMENDOLA Parallel Session: CM4 - Tensions on LCDM cosmological model and model-independent constraints Description: This session will be devoted to study the ability of the LCDM model (the "concordance model" of cosmology) to describe the modern cosmological observations and compare with model-independent analyses as well as with a variety of alternative theoretical frameworks (in particular dynamical dark energy models of different kinds) which have been proposed to describe the same set of observations. Among the hot subjects that should be discussed in this session we have e.g. i) The discordant measurements between the Hubble parameter determination from the CMB data and the distance ladder measurements, ii) The long standing mismatch between the geometry and structure formation data, in particular the sigma_8 tension, a quantity whose value in the LCDM is predicted to be larger than what is needed to improve the adjustment of the structure formation data obtained from redshift space distortions and other methods, and iii) The need to analyse data in a model independent way. Discussions are also necessary concerning possible unaccounted systematic effects. |
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Masaki ANDO Parallel Session: GW5 - DECIGO Description: In this session, we will discuss science cases and technologies related to a space gravitational-wave (GW) antenna mission DECIGO and its precursor mission B-DECIGO. In twenty years, 3rd generation ground-based detectors (ET and CE) and a space mission LISA would be in operational. A space mission B-DECIGO will have an original design to have observation frequency band around 0.1Hz, which is between the ground-based detectors and LISA. This provides us original science possibilities: sciences only by B-DECIGO or those by combinations with the other GW or electro-magnetic wave observations. DECIGO is the future and upgraded mission of B-DECIGO, with an ambitious scientific target to observe the background GWs from the early universe. Feasibility of these missions will be also discussed from technical point of view in this session. |
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Carlos ARGÜELLES Parallel Session: DM1 - Interacting Dark matter Description: The session is devoted to the physics of all possible aspects of interacting dark matter, including self interactions of dark matter and their cosmological consequences, or interactions of dark matter with ordinary matter and their consequences. Various types of dark matter in various models, including supersymmetry, are considered. Dark matter searches also constitute part of the session's subject. |
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Matthew G. BARING Parallel Session: HE6 - Cosmic Ray Acceleration, Radiation and Neutrinos in Extragalactic Jets Description: Extragalactic jets associated with supermassive black holes in distant active galaxies are the origins of luminous and highly-variable emission across the electromagnetic spectrum. They are also believed to be putative sites for cosmic ray acceleration and very high energy (VHE) neutrino genesis. This multi-messenger session will address the synergies between particle acceleration and leptonic and hadronic processes in jets in blazars and radio galaxies, highlighting recent theoretical and observational results in this astroparticle frontier. Emphases will include associations between blazars and VHE neutrino events reported by the IceCube collaboration, the possibilities of them serving as sources of Ultra-High Energy Cosmic Rays, and the interconnection between mechanisms of particle acceleration (shocks, stochastic or magnetic reconnection) and radiative signatures at all wavebands. Broader connections to jets in gamma-ray bursts and binary merger events will be included. |
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Ulisses BARRES DE ALMEIDA Parallel Session: HE8 - Astronomical Data in the Multi-messenger era Description: Much has been done in recent years, especially in space astronomy, to offer open access, interoperable platforms and data services, demonstrating how natural is the evolution towards a more transparent and inclusive ecosystem of tools and services for the data-intensive astronomy of the near-future. Further efforts are nevertheless still necessary to consolidate, standardise and expand services in the current era of multi-band / multi-messenger astronomy, and in order to optimise the utility of the data services that form the fundamental interface between theoretical and observational astrophysics. This session wishes to focus on the status of astronomical data services and initiatives, and on current paradigms in astronomical data processing which aim to promote a significant data-driven surge in training, education and scientific discovery. A special focus is set towards new proposals to deal with emerging issues in the future of big-data astronomy, and on efforts in the framework of the Open Universe initiative. |
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Damien BEGUE Parallel Session: GB4 - Photospheric emission in GRBs Description: Early models of cosmological gamma-ray bursts predicted the observed spectrum to be nearly blackbody. Observations were at odds with this prediction, and different theoretical models assuming optically thin emission have been put forward. However, models of such non thermal emission appear to be inconsistent with observations of steep spectra in early phases of many gamma-ray bursts. Instead models involving photospheric emission producing modified blackbody spectra explain such observed spectra quite naturally. We will discuss physical aspects of photospheric emission in relativistic outflows and cocoons, as well as observational issues related to the detection of such a photospheric component in GRBs. Special attention will be given to sub-photospheric dissipation mechanisms, geometric and dynamical effects, jet content, and presence of additional emission mechanisms. |
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Krzysztof BELCZYNSKI Parallel Session: BN3 - NS-NS and NS-WD mergers Description: NS-NS mergers are at the center of high energy astrophysics and they generate some of the most spectacular phenomena; from gamma-ray bursts, to optical transients to high-frequency gravitational waves (LIGO/Virgo sources). However, much neglected NS-WD mergers can produce very similar events alas with potentially different characteristics. They can also produce gamma-ray bursts, optical transients and low-frequency gravitational waves (LISA sources). Our main focus during this session is to discuss the most recent advancements in observational and theoretical studies of NS-NS and NS-WD mergers. In particular, we would like to assess and compare these two types of mergers in context of their progenitors (stellar evolution), external environment (merger sites/host galaxies), physics of merger (general relativity/gravitational waves) and the explosive aftermath (EM counterparts). |
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Vladimir BELINSKI Parallel Session: EU2 - Quantum Fields Description: This session is dedicated to the all aspects of the theory of quantum fields. Special interest we will pay to the quantum fields in curved space-time and to any results having applications in General Relativity. |
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Stefano BELLUCCI Parallel Session: AT7 - Theories of gravity: alternatives to the cosmological and particle standard models Description: In the standard model of cosmology, the ΛCDM model based on Einstein’s General Relativity, dark energy is introduced completely ad hoc in order to explain the present acceleration of the universe. The model requires also the introduction of dark matter dominating (by far) ordinary baryonic matter but yet undetected in the laboratory, and it suffers from astrophysical problems. Modifying gravity is a possible alternative, and many such proposals have been presented in recent years. Likewise, the standard model of particle physics is unable to incorporate all the current particle phenomenology and proposed dark matter candidates. Cosmology and particle physics come together in the early universe and, surprisingly, also in theories and models of the present, accelerating universe. This session is formulated in a wide framework to include several topics related to these problems, and spanning alternative theories of gravity and cosmology, alternatives to the ΛCDM model, quantum field theory applied to gravity, extensions of the standard model of particle physics, and dark energy and dark matter from a particle physics point of view. This session represents the interplay between, and the efforts to match, particle physics and cosmology, giving particular emphasis to the role played by particle quantum field theory in the early and the late universe. |
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Zurab BEREZHIANI Parallel Session: DM2 - Dark Matter and rare processes Description: This session will focus on new results and ideas in Dark Matter direct detection and in searches for rare processes, which are important topics in underground Physics. Both contributions on experimental and theoretical efforts are welcome. |
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Eric BERGSHOEFF Parallel Session: AT6 - Applied Newton-Cartan Geometry Description: Despite the huge success of General Relativity, recently the realization has dawned that non-relativistic gravity encapsulates much more than just Newtonian gravity. Thus, Newton-Cartan geometry can be used to describe gravity at velocities that are low with respect to the speed of light, but with strong gravitational fields. Hence non- relativistic gravity is emerging as a novel tool to get a hold on the non-perturbative properties of non-relativistic models that are otherwise difficult to access. Effective field theories in a Newton-Cartan background have been studied in condensed matter and used to describe a variety of non-relativistic systems such as the Fractional Quantum Hall effect. Parallel to this development, recent studies of non-AdS holography involving Lifshitz spacetimes have led to field theories with non-relativistic scaling, that are naturally coupled to an extension of Newton-Cartan geometry that includes torsion, with twistless torsion being a special case in which there are surfaces of absolute simultaneity. Besides the holographic and effective field theory applications, there have been a host of other recent applications of Newton-Cartan geometry in different fields ranging from hydrodynamics to modified gravity. For instance, it has been shown that Hořava-Lifshitz gravity and novel extensions can be described using dynamical Newton-Cartan geometry. The field of Applied Newton-Cartan Geometry is currently a rapidly developing field which is attracting researchers from different directions, that are inspired to contribute to uncovering the many possible interconnections and applications. |
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Rita BERNABEI Parallel Session: DM2 - Dark Matter and rare processes Description: This session will focus on new results and ideas in Dark Matter direct detection and in searches for rare processes, which are important topics in underground Physics. Both contributions on experimental and theoretical efforts are welcome. |
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Marco BERSANELLI Parallel Session: CM5 - Present and future of CMB observations Description: Observations of the cosmic microwave background (CMB) continue to offer wonderful opportunities to deepen our understanding of cosmology and fundamental physics. This session will focus on recent advances and future plans for precision measurements of the CMB. We welcome presentations of recent results and ongoing efforts to measure CMB polarization, CMB frequency spectrum, Sunyaev-Zel'dovich effect, and relevant astrophysical sources. We seek to stimulate discussion on issues related to calibration, systematic effects, and foreground components for ground-based, balloon-borne, and satellite measurements. |
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Carlo Luciano BIANCO Parallel Session: GB11 - Plasma acceleration and transparency in GRBs Description: In this parallel session we discuss the hydrodynamic evolution of the baryon-loaded plasma of photons and electron-positron pairs (fireshell) in the following aspects: (1) The conservation of total energy (thermal energy plus kinetic energy) in the ultra relativistic expansion of the plasma up to the transparency point. The thermal energy is then emitted accounting for the observed thermal component of the P-GRB, while the kinetic energy continually drives the fireshell accounting for later emission processes after the P-GRB. (2) Using observed data of thermal P-GRB emission energy, temperature, and width, as well as total emission energy, to infer the baryon load and the Lorentz gamma factor of the fireshell. These studies bring insight into the properties of baryon-loaded plasma acceleration and transparency in GRBs. |
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Donato BINI Parallel Session: BN9 - Gravitational interaction of n-pole point particles and higher-spin fields Description: Understanding the dynamics of test bodies/test fields with n-polar structure within special solutions of the Einstein's field equations like black holes is a hot topic in General Relativity today. While the case of dipolar particles (described either by the classic Mathisson-Papapetrou-Dixon model or by a Hamitonian) is well studied and the results are satisfying enough, the case of bodies with quadrupolar, octupolar (and beyond) structure is poorly investigated because of the various underlying difficulties. We encourage talks from a classical general relativity point of view, from a Hamiltonian point of view, from the effective-field-theory point of view, from the scattering amplitude, showing exact, approximated as well as fully numerical results, with the aim of facilitating communications among researchers in different areas and working with different techniques. We are especially open to accept talks introducing new techniques, as in the effective-field-theory and scattering amplitude context, which might offer computational advance with respect to the more traditional ones. There will be both review talks as well as contributed talks, time span of which will depend on the number of speakers. |
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Nigel BISHOP Parallel Session: GW6 - The Role of Numerical Relativity in Gravitational Wave Observations Description: The session is open for talks on all aspects of numerical relativity related to the calculation of gravitational waves from astrophysical sources. This includes the development and applications of codes for BH-BH, BH_NS and NS-NS mergers, as well as the development of relevant theory or computational methods. |
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David BLAIR Parallel Session: ED1 - Teaching Einsteinian Physics to School Students Description: Einstein played a pivotal role in the development of quantum physics, and his theory of general relativity represents our best understanding of the macroscopic Universe, describing, with great precision, the interplay between the geometry of space-time and its matter and energy content. Besides its outstanding importance for science, Einsteinian physics, encompassing quantum mechanics and relativity underpins almost all modern technology, as epitomised by the semiconductor physics and GPS navigators in smart phones. Gravitational wave detectors, which are quantum instruments for measuring spacetime can only be understood in an Einsteinian context. Despite all this, the Newtonian concepts of space, time, matter and radiation, which are in conflict with modern physics, are still taught in schools worldwide. In this session we will discuss and present research findings focussed on the necessity and possibility of grounding school education in Einsteinian concepts across the years K-12. Papers are invited on all aspects of the teaching and learning of Einsteinian physics including curriculum proposals, educational research results and approaches for connecting Einsteinian concepts to important Newtonian tools. |
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Luc BLANCHET Parallel Session: BN6 - Post-Newtonian expansion and analytic approximations Description: This session will cover post-Newtonian expansions for equations of motion and radiation field, analytic approaches to self-force problems, BH perturbations, tests of GR using gravitational waves, analytic approximations in alternative theories. |
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Christian BRACCO Parallel Session: HR1 - History of Relativity Description: In this historical session, we will focus on the history of the discovery of gravitational waves, recently detected by the Ligo-Virgo collaboration, to commemorate their prediction a century ago. More generally, we will look back at the history of general relativity and some of its main contributors but also discuss papers on other topics of historical interest with a particular focus on the connections between Einstein and his theories with Italy. |
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Fabio BRISCESE Parallel Session: ES1 - Exact Solutions in Four and Higher Dimensions: Mathematical Aspects Description: This Parallel Session will be devoted to a variety of mathematical methods, associated mathematical structures and other mathematical aspects of the analysis of Einstein's field equations, constructing exact solutions and development of various solution generating techniques, interrelations of different approaches, classifications of solutions, studies of the structures and geometrical properties of particular solutions and classes of solutions in General Relativity as well as in various gravity, string gravity and supergravity models in four and higher dimensions. |
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Enrico BOZZO Parallel Session: HE7 - Future missions for high-energy astrophysics Description: The detection and study of high-energy photons from cosmic sources and phenomena has been revolutioning modern astrophysics since the '60s, providing unique clues to, e.g., the existence and properties of black-holes and neutron stars, hot gas and dynamics in galaxy clusters, non-thermal emission processes, engine and extrem physics of active galactic nuclei, shock-emission in pulsar-winf nebula and supernova remnant, as well as the discovery of peculiar and mysterious phenomena like Gamma-Ray Bursts. With the very recent birth of multi-messenger astrophysics, high-energy astorphysics is going to play an even stronger role in astrophysics and cosmology. This session is focused on the description of the many X-/Gamma-ray astrophysics space missions and experiments currently under development or at the proposal / study stage worldwide, that will provide a substantial contribution to the advancement of modern science in the next two decades. |
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Carlo BURIGANA Parallel Session: CM2 - Cosmic Backgrounds from radio to far-IR Description: This parallel session will focus on the interpretation and perspectives for cosmology and astrophysics coming from cosmic backgrounds from radio to far-IR, in both temperature and polarization. While the final release and corresponding results from the Planck mission is forthcoming, sub-orbital experiments are investigating on CMB polarization anisotropies and searching for primordial gravitational waves, and future CMB missions of different scales are under study. The sub-mm / far-IR domain, crucial for high-frequency foreground mitigation, allows to study a number of astrophysical cosmology topics, including the early phases of star and galaxy formation. In parallel, on-going and future radio projects promise to shed light on the dawn ages and reionization epoch and to provide 3D images of the Universe evolution. The authors of both invited and contributed talks are encouraged to underline the connection between astrophysical and cosmological results. |
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Gianluca CALCAGNI Parallel Session: QG2 - Quantum Gravity Phenomenology Description: Talks presented in this session will focus on the possibility of finding experimental manifestations of effects introduced at the Planck scale, relevant for the study of the quantum-gravity problem. |
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Antonio CAPONE Parallel Session: HE2 - High Energy Astrophysical Neutrino detection Description: The recent IceCube discovery of a flux of High Energy Neutrinos, in excess of the atmospheric component, has opened a new chapter of experimental physics: the High Energy Neutrino Astrophysics. Neutrino, being neutral and only weakly interacting, can travel intergalactic distances without being deflected by magnetic fields and/or affected by interactions with matter: they are a perfect tool for astronomy. Galactic and extragalactic objects where hadronic matter can be accelerated to energies exceeding some TeV, can be considered sources of High Energy Neutrinos. Within this parallel session the experimental efforts going on at present for the HE Astrophysical neutrino detection as well as the models for the emission of Astrophysical neutrinos will be discussed. HE Neutrino detection will be discussed in the contest of a multi-messenger astrophysics. |
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Salvatore CAPOZZIELLO Parallel Session: AT1 - Extended Theories of Gravity and Quantum Cosmology Description: Extended Theories of Gravity can be considered a new paradigm to cure shortcomings of General Relativity at infrared and ultraviolet scales. They are an approach that, by preserving the undoubtedly positive results of Einstein's Theory, is aimed to address conceptual and experimental problems recently emerged in Astrophysics, Cosmology and High Energy Physics. In particular, the goal is to encompass, in a self-consistent scheme, problems like Inflation, Dark Energy, Dark Matter, Large Scale Structure and, first of all, to give at least an effective description of Quantum Gravity. The basic idea of such an approach is to generalize the Hilbert-Einstein action relaxing the hypothesis that it must be linear in the Ricci scalar R. In principle, any f(R) function of R or other curvature invariants like Ricci, Riemann or Weyl tensors can be considered assuming effective theories of gravity. The general philosophy is that the true and final theory of gravity could be reconstructed, in principle, matching the phenomenology from infrared scales (astrophysics and cosmology) to ultraviolet scales (quantum field theory) going beyond a trial and error approach. |
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Roberto CAPUZZO DOLCETTA Parallel Session: GW8 - Dense stellar environments as sites of gravitational wave emission Description: Dense stellar environments (from open star clusters to nuclear star clusters) are suited environments to study compact remnants (white dwarfs, neutron star and black holes, from stellar to supermassive) either as single or multiple objects. In this session, we will present modern results of the evolution of such compact massive objects in their environment, up to their possible final mergers and associated bursts of gravitational waves. |
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Sandip CHAKRABARTI Parallel Session: AC1 - Spectral and Temporal properties of Black Holes and neutron stars and the theoretical models Description: This session brings together all the scientists who are interested in relativistic astrophysics around galactic, extra-galactic and intermediate mass black holes. We welcome papers on the following topics and other from related topics: 1. Theory of accretion disks, outflows and jets 2. emission processes from the disks and jets 3. Polarization properties of radiations from disks and jets 4. Fitting of satellite data by theoretical models 5. Evidences for disk-jet connections 6. Numerical simulations of hydrodynamic and magneto-hydrodynamic equations in black hole geometry |
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Jens CHLUBA Parallel Session: CM3 - Future Steps in Cosmology with CMB Spectral Distortions Description: The cosmic microwave background (CMB) has proven itself to be an invaluable source of information about the Universe we live in. Over the past decades, we have mostly harvested information from CMB anisotropies, with the next major target being B-mode polarization patterns caused by cosmic gravitational waves from inflation. However, also the CMB energy spectrum — through departures from the perfect blackbody, often referred to as CMB spectral distortions — can tell us a tail about energy release processes affecting the thermal history of the Universe in the pre-recombination era, less that 400,000 year after the big bang. The purpose of this session is to bring together experts in theory and observation interested in testing fundamental physics with CMB spectral distortions. It will provide an opportunity to discuss new theoretical ideas with the leaders of this emerging young field, providing a stimulating environment and the starting point for new studies. The program will include review talks on the state-of-the art of spectral distortion science, as well as discussions of new experimental opportunities. |
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Alessandro DE ANGELIS Parallel Session: HE1 - Very High Energy Gamma Rays Description: The development of the atmospheric Cherenkov imaging technique for ground-based gamma-ray astronomy has led to a rapid growth in the number of known sources and source types of Very-High-Energy (above 30 GeV) gamma rays, and to unveiling mysteries of cosmic rays. Large field-of-view instruments like HAWC are also providing new information, in particular on extreme accelerators. The future is bright: the construction of the Cherenkov Telescope Array (CTA) has started, and new instrument designs for multi-TeV detection have been proposed. Next-generation telescopes are under construction and will increase dramatically the knowledge available at this extreme end of the cosmic electromagnetic spectrum. VHE gamma-ray astronomy has a special value in the multimessenger context, i.e., in conjunction with neutrino and gravitational wave detection. |
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Paolo DE BERNARDIS Parallel Session: HR2 - Angelo Secchi and Astrophysics Description: Angelo Secchi (1818-1878) was the most relevant italian astronomer of 1800, capable to develop and spread rapidly the techniques of spectroscopy applied to the stars and to the Sun. Author of more than 770 publications, his production was seminal also in Meteorology, Idrology, Oceanography and Topography. The books on The Sun and The stars reached a vaste public maintaining the top level many decades after his death. The spectral classification of stars has in Secchi the pioneer, opening the way to the Harvard catalogues. The NASA dedicated to Secchi a special mission for the study of the Sun, which many results and publications still in progress. We will focus on the vaste scientific activity of Angelo Secchi, as well as on his social and scientific milieu. |
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Mariafelicia DE LAURENTIS Parallel Session: AT1 - Extended Theories of Gravity and Quantum Cosmology Description: Extended Theories of Gravity can be considered a new paradigm to cure shortcomings of General Relativity at infrared and ultraviolet scales. They are an approach that, by preserving the undoubtedly positive results of Einstein's Theory, is aimed to address conceptual and experimental problems recently emerged in Astrophysics, Cosmology and High Energy Physics. In particular, the goal is to encompass, in a self-consistent scheme, problems like Inflation, Dark Energy, Dark Matter, Large Scale Structure and, first of all, to give at least an effective description of Quantum Gravity. The basic idea of such an approach is to generalize the Hilbert-Einstein action relaxing the hypothesis that it must be linear in the Ricci scalar R. In principle, any f(R) function of R or other curvature invariants like Ricci, Riemann or Weyl tensors can be considered assuming effective theories of gravity. The general philosophy is that the true and final theory of gravity could be reconstructed, in principle, matching the phenomenology from infrared scales (astrophysics and cosmology) to ultraviolet scales (quantum field theory) going beyond a trial and error approach. |
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Angela DI VIRGILIO Parallel Session: PT3 - Experimental Gravitation Description: In the session "Experimental Gravitation" we cover all laboratory experiments testing gravity and the structure of space-time using classical matter, quantum matter, light and atomic interferometry. We are first dealing with experiments exploring the structure of space-time as it is encoded in the Einstein Equivalence Principle (EEP). This includes tests of the Universality of Free Fall, the Universality of the Gravitational Redshift, and Local Lorentz Invariance. These tests fix the space-time geometry. The next group of tests will explore the field equation of gravity which in most cases is encoded in the PPN formalism; more general formalisms like Finsler geometry also needs to be included. The third group of tests deals with testing the predictions of GR. This also will include applications like geodesy, positioning and metrology. |
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Valerio FARAONI Parallel Session: AT7 - Theories of gravity: alternatives to the cosmological and particle standard models Description: In the standard model of cosmology, the ΛCDM model based on Einstein’s General Relativity, dark energy is introduced completely ad hoc in order to explain the present acceleration of the universe. The model requires also the introduction of dark matter dominating (by far) ordinary baryonic matter but yet undetected in the laboratory, and it suffers from astrophysical problems. Modifying gravity is a possible alternative, and many such proposals have been presented in recent years. Likewise, the standard model of particle physics is unable to incorporate all the current particle phenomenology and proposed dark matter candidates. Cosmology and particle physics come together in the early universe and, surprisingly, also in theories and models of the present, accelerating universe. This session is formulated in a wide framework to include several topics related to these problems, and spanning alternative theories of gravity and cosmology, alternatives to the ΛCDM model, quantum field theory applied to gravity, extensions of the standard model of particle physics, and dark energy and dark matter from a particle physics point of view. This session represents the interplay between, and the efforts to match, particle physics and cosmology, giving particular emphasis to the role played by particle quantum field theory in the early and the late universe. |
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Victor FLAMBAUM Parallel Session: PT4 - Variation of the fundamental constants, violation of the fundamental symmetries and dark matter Description: Search for the space-time variation of the fundamental constants is a very broad research area based on numerous astrophysical and geophysical observations and laboratory experiments. Recent results show that this is also a very efficient method to search for low-mass dark matter. Traditional searches for the scattering of dark-matter particles off nuclei have not yet produced a strong positive result. The challenge with such traditional searches is that they look for effects that are fourth power in a very small interaction constant. However, there are effects of dark matter that are first power in the interaction constant, which may give an enormous advantage. Low-mass bosonic dark-matter particles produced after the Big Bang form an oscillating classical field and/or topological defects. Various non-gravitational interactions of ordinary matter with these fields can produce a cosmological evolution of the fundamental constants, such as the strengths of the fundamental forces (including electromagnetism), as well as the masses of particles. Variations in these physical constants leave characteristic fingerprints on physical processes that take place from as early as a second after the birth of the Universe until the present day. Effects of varying physical constants include changes in the primordial abundances of light elements, cosmic microwave background fluctuations, quasar absorption spectra and pulsar timing. Further progress may be achieved using atomic clocks, laser-interferometry experiments (such as LIGO, which has detected gravitational waves), optical cavities and other laboratory devices. Other effects of dark matter include oscillating spin-precession effects, oscillating parity-violating effects and oscillating electric dipole moments. The first results of observations, which have improved the sensitivity to the interaction of dark matter with the photon, electron, nucleons, quarks, gluons, Higgs boson, W and Z bosons by up to 15 orders of magnitude, have already been published. Astrophysical observations indicate that 85% of the matter content in the Universe is due to dark matter, the identity and properties of which remain a mystery. Traditional searches for the scattering of dark matter articles off nuclei have not yet produced a strong positive result. The challenge with these traditional searches is that they look for effects that are fourth or second power in a very small interaction constant. However, there are effects of the first power in the interaction constants, which may give an enormous advantage. The low mass boson dark matter particles produced after Big Bang form an oscillating classical field and/or topological defects. Interactions with these fields produce a cosmological evolution of the fundamental constants such as the strength of the fundamental forces (including electromagnetism), as well as the masses of the particles. Variations in these physical constants leave characteristic fingerprints on physical processes that take place from as early as a second after the birth of the Universe until the present day. The effects include change of the primordial abundances of light elements, cosmic microwave background fluctuations, quasar spectra and pulsar timing. Further progress may be achieved using atomic clocks, laser interferometry experiments (such LIGO which detected gravitational waves), silicon cavities and other laboratory devices. Other effects of dark matter include oscillating spin-precession, oscillating parity violating effect and oscillating electric dipole moments. First results of the observations which improved sensitivity to interaction of dark matter with photon, electron, quarks, Higgs, W and Z boson by up to 15 orders of magnitude have already been published. |
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Sergio FRASCA Parallel Session: GW9 - Advanced Data-Analysis Techniques for Gravitational-Wave Detection Description: With the recent advent of the GW-astronomy era we started to hone the comprehension of some of the objects populating our Universe. A broader picture will be however provided by the detection of the other missing GW signals, such as continuous waves, a stochastic background of both astrophysical and cosmological origin, and bursts from supernovae explosions. The use of robust and groundbreaking data analysis techniques, including pattern recognition and machine learning algorithms, will allow us to improve the sensitivity to detect GW signals in the data taken by the advanced LIGO-Virgo detectors. This session is devoted to review the current efforts to develop revolutionary and cutting-edge data-analysis techniques for GW detection. |
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Federico FRASCHETTI Parallel Session: HE6 - Cosmic Ray Acceleration, Radiation and Neutrinos in Extragalactic Jets Description: Extragalactic jets associated with supermassive black holes in distant active galaxies are the origins of luminous and highly-variable emission across the electromagnetic spectrum. They are also believed to be putative sites for cosmic ray acceleration and very high energy (VHE) neutrino genesis. This multi-messenger session will address the synergies between particle acceleration and leptonic and hadronic processes in jets in blazars and radio galaxies, highlighting recent theoretical and observational results in this astroparticle frontier. Emphases will include associations between blazars and VHE neutrino events reported by the IceCube collaboration, the possibilities of them serving as sources of Ultra-High Energy Cosmic Rays, and the interconnection between mechanisms of particle acceleration (shocks, stochastic or magnetic reconnection) and radiative signatures at all wavebands. Broader connections to jets in gamma-ray bursts and binary merger events will be included. |
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Filippo FRONTERA Parallel Session: HE3 - The first Chinese X-ray astronomy mission Insight-HXMT at MGXV Description: The session will be devoted to present the first scientific results obtained with the Insight-HXMT mission. Insight-HXMT is the first Chinese space X-ray telescope satellite jointly funded by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS), and successfully launched on 15 June 2017. The payload includes large area instruments that cover a very broad energy band (1-300 keV). The active shielding of the high energy instrument (HE) is also exploited as a Gamma-Ray Burst Monitor, with a passband from 200 to 800 keV in the regular mode, and from 200 keV to 2 MeV in the GRB mode. |
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Chris L. FRYER Parallel Session: GB5 - GRBs and the Afterglow Description: The nature and origin of cosmological gamma-ray bursts remains one of the major mysteries in astrophysical transients. Observing and understanding the GRB afterglow is one of the strongest probes placing constraints on both the engine and surrounding environment of the GRB and these observations are key to unraveling the mystery of these cosmic explosions. There now exist observations in multiple wavelengths ranging from the radio, optical, X-ray, gamma-ray, etc. up to the TeV range. Each of these provides insight into the multifaceted paradigm of GRB origin and evolution. In this parallel session we encourage papers dealing with all aspects of the origin of GRBs and the associated afterglow in all wavelength bands. |
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Paolo GIOMMI Parallel Session: HE5 - Neutrino Astronomy Description: After a time in which only TWO neutrino sources were known (the Sun and SN 1987A) we are now entering a new era in which the first associations between neutrino and electromagnetic sources are being made. This session would like to focus on the status of neutrino astronomy from the observational, theoretical, and population points of view by reviewing: - results from neutrino experiments; - status of the identification of the astrophysical sources of neutrinos; - classes of most likely emitters; - theoretical perspective; - the way forward. |
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Gabriele GIONTI Parallel Session: HR2 - Angelo Secchi and Astrophysics Description: Angelo Secchi (1818-1878) was the most relevant italian astronomer of 1800, capable to develop and spread rapidly the techniques of spectroscopy applied to the stars and to the Sun. Author of more than 770 publications, his production was seminal also in Meteorology, Idrology, Oceanography and Topography. The books on The Sun and The stars reached a vaste public maintaining the top level many decades after his death. The spectral classification of stars has in Secchi the pioneer, opening the way to the Harvard catalogues. The NASA dedicated to Secchi a special mission for the study of the Sun, which many results and publications still in progress. We will focus on the vaste scientific activity of Angelo Secchi, as well as on his social and scientific milieu. |
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Jonathan GRANOT Parallel Session: GB7 - Lessons from GW170817 / GRB170817A Description: The first detection of a gravitational wave signal from a binary neutron star merger, GW 170817, was also promptly accompanied by an electromagnetic counterpart in the form of a short duration gamma-ray burst, GRB 170817A. A huge global effort of multi-wavelength follow-up observations has led to the detection of kilonova emission in the optical, UV and NIR, as well as long-lived X-ray to radio afterglow emission. This unique event has a wide range of implications, ranging from constraints on the neutron star equation of state and maximal mass, through the important role of such binary mergers in r-process nucleosynthesis in the universe, to the type of remnant that was produced, and the properties of the outflows that are produced in these mergers. This session will discuss the observations and theoretical implications of this extraordinary event. |
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Eva HACKMANN Parallel Session: AC3 - Accretion discs and jets Description: Accretion disks are the systems which most closely approach compact objects and, therefore, are an ideal system to explore the strong gavity regime. The basic physical mechanism of accretion is clear, however, several open questions remain. This includes for instance the effective equation of motion for continua in strong gravitational fields, the viscosity problem, the stability on large time scales, the "feeding" of active galactic nuclei, the structure of the inner part of accretion disks, the connection between accretion disks and jets, and the impact of accretion disc observations on generalized theories of gravity or matter models. In this session we focus on the theoretical modeling of accretion in the strong gravitational field and related phenomena, including but not limited to: (i) foundations of relativistic hydrodynamics (ii) relativistic turbulence and viscosity (iii) self-gravitational and self-electromagnetic fields (iv) modeling of accretion discs, also in various spacetimes and theories (v) accretion discs and jet creation. |
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Alexander KAMENSHCHIK Parallel Session: EU2 - Quantum Fields Description: This session is dedicated to the all aspects of the theory of quantum fields. Special interest we will pay to the quantum fields in curved space-time and to any results having applications in General Relativity. |
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Tejinder KAUR Parallel Session: ED1 - Teaching Einsteinian Physics to School Students Description: Einstein played a pivotal role in the development of quantum physics, and his theory of general relativity represents our best understanding of the macroscopic Universe, describing, with great precision, the interplay between the geometry of space-time and its matter and energy content. Besides its outstanding importance for science, Einsteinian physics, encompassing quantum mechanics and relativity underpins almost all modern technology, as epitomised by the semiconductor physics and GPS navigators in smart phones. Gravitational wave detectors, which are quantum instruments for measuring spacetime can only be understood in an Einsteinian context. Despite all this, the Newtonian concepts of space, time, matter and radiation, which are in conflict with modern physics, are still taught in schools worldwide. In this session we will discuss and present research findings focussed on the necessity and possibility of grounding school education in Einsteinian concepts across the years K-12. Papers are invited on all aspects of the teaching and learning of Einsteinian physics including curriculum proposals, educational research results and approaches for connecting Einsteinian concepts to important Newtonian tools. |
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Michael KIESSLING Parallel Session: AT2 - The Einstein-Infeld-Hoffmann Legacy in Mathematical Relativity Description: In their famous 1938 Annals of Mathematics paper: 'The Gravitational Equations and the Problem of Motion,' Einstein, Infeld, and Hoffmann claimed that the field equations of general relativity theory alone determine the equations of motion of matter particles, viewed as naked point-singularities in space-like slices of spacetime. Their claim was generalized to charged naked point-singularities by Infeld's student Wallace in 1941. Although non-rigorous and full of questionable assumptions, these works have become the template of many follow-up studies, in particular the computation of gravitational wave signals. Part 1 of this session draws attention to recent rigorous advances in our understanding of the classical joint initial value problem for N point-charges and their electromagnetic fields in special and general relativity. This includes a local well-posedness theorem which uses an electromagnetic vacuum law that avoids the infinity problems of the Maxwell-Lorentz field equations. Part 2 proposes a `deformation quantization' of the classical structure of part 1 inspired by Einstein's 'Führungsfeld' idea: the singularities of mildly singular general-relativistic spacetimes are guided by solutions of Dirac-type wave equations, showing that GR and QM can peacefully co-exist (in a suitable sense). Both electrons and photons will be treated in this manner. |
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Sang Pyo KIM Parallel Session: SF1 - Strong (EM) Fields Physics and Laboratory Astrophysics Description: Strong electromagnetic and gravitational fields are two of the most important ingredients for astrophysics and cosmology. This session is dedicated to all theoretical aspects of high field and/or energetic phenomena due to strong electromagnetic fields and/or gravity in ground laboratories as well as astrophysics and cosmology, such asSchwinger pair creation and back-reaction,charged particle acceleration, and vacuum polarization and nonlinearity of strong electromagnetic fields and magnetogenesis. It is also dedicated to experimental and theoretical aspects of laboratory astrophysics and astrophysical observations related to strong field physics, such as intense lasers plasma acceleration, plasma interaction with strong electromagnetic fields, radiation from accelerating charges, observation of birefringence in neutron stars, simulation of strong gravity effects etc. |
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Marcin KISIELOWSKI Parallel Session: QG1 - Loop Quantum Gravity Description: |
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Jutta KUNZ Parallel Session: BH7 - Black Holes in Higher Dimensions (Black Rings and Black Strings) Description: |
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Claus LÄMMERZAHL Parallel Session: PT3 - Experimental Gravitation Description: In the session "Experimental Gravitation" we cover all laboratory experiments testing gravity and the structure of space-time using classical matter, quantum matter, light and atomic interferometry. We are first dealing with experiments exploring the structure of space-time as it is encoded in the Einstein Equivalence Principle (EEP). This includes tests of the Universality of Free Fall, the Universality of the Gravitational Redshift, and Local Lorentz Invariance. These tests fix the space-time geometry. The next group of tests will explore the field equation of gravity which in most cases is encoded in the PPN formalism; more general formalisms like Finsler geometry also needs to be included. The third group of tests deals with testing the predictions of GR. This also will include applications like geodesy, positioning and metrology. |
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Paola LEACI Parallel Session: GW9 - Advanced Data-Analysis Techniques for Gravitational-Wave Detection Description: With the recent advent of the GW-astronomy era we started to hone the comprehension of some of the objects populating our Universe. A broader picture will be however provided by the detection of the other missing GW signals, such as continuous waves, a stochastic background of both astrophysical and cosmological origin, and bursts from supernovae explosions. The use of robust and groundbreaking data analysis techniques, including pattern recognition and machine learning algorithms, will allow us to improve the sensitivity to detect GW signals in the data taken by the advanced LIGO-Virgo detectors. This session is devoted to review the current efforts to develop revolutionary and cutting-edge data-analysis techniques for GW detection. |
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Andrei LEBED Parallel Session: EU2 - Quantum Fields Description: This session is dedicated to the all aspects of the theory of quantum fields. Special interest we will pay to the quantum fields in curved space-time and to any results having applications in General Relativity. |
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Jerzy LEWANDOWSKI Parallel Session: QG1 - Loop Quantum Gravity Description: |
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Vladimir LIPUNOV Parallel Session: BN8 - Relativistic Binary Stars Merging: Population Synthesis ©/or Multimessanger Observations Description: |
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Meike LIST Parallel Session: PT6 - Fundamental physics in Space Description: Over the last years fundamental physics became an important field of space science. At the moment there are comparably many fundamental physics space mission under way. More and more missions (i) focusing on proving e.g. General Relativity Theory like MICROSCOPE, LISA, and GP-B, or (ii) using Gravity for Earth observation like GRACE and GRACE-FO, are already in orbit or in preparation to be launched within the next years. In this session we will focus on present missions, their status and scientific results, as well as on new mission concepts and newly developed space technologies. |
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Francesco LONGO Parallel Session: GB6 - GeV emission from Gamma Ray Bursts Description: GeV observations of gamma-ray bursts (GRBs) by the Fermi/LAT and AGILE space telescopes over the past decade have opened a new era in the study of GRBs. This session will discuss recent observations of GRBs at GeV energies and its relation to the prompt <~ MeV emission, the long-lived afterglow emission, and correlated searches at TeV energies. The theoretical implications of these observations will be also discussed, which range from the progenitor nature to the prompt GRB emission mechanism and outflow Lorentz factor and composition, through the GRB jet launching and acceleration mechanism, to particle acceleration in collisionless shocks or magnetic reconnection, and constraints on Lorentz invariance violation. |
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Duncan LORIMER Parallel Session: GB1 - Fast radio bursts: observations, ideas and prospects Description: This session will include invited talks and contributed talks to discuss the current observational progress, theoretical ideas, as well as future perspectives in the study of fast radio bursts, a new type of cosmological transients whose nature is currently unknown. |
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Francisco LOBO Parallel Session: AT3 - Wormholes, Energy Conditions and Time Machines Description: The General Theory of Relativity has been an extremely successful theory, with a well established experimental footing, at least for weak gravitational fields. Its predictions range from the existence of black holes, gravitational radiation to the cosmological models, predicting a primordial beginning, namely the big-bang. All these solutions have been obtained by first considering a plausible distribution of matter, and through the Einstein field equation, the spacetime metric of the geometry is determined. However, one may solve the Einstein field equation in the reverse direction, namely, one first considers an interesting and exotic spacetime metric, then finds the matter source responsible for the respective geometry. In this manner, it was found that some of these solutions possess a peculiar property, namely 'exotic matter,' involving a stress-energy tensor that violates the null energy condition. These geometries also allow closed timelike curves, with the respective causality violations. These solutions are primarily useful as 'gedanken-experiments' and as a theoretician's probe of the foundations of general relativity, and include traversable wormholes and superluminal 'warp drive' spacetimes. In this parallel session, in addition to extensively exploring interesting features, in particular, the physical properties and characteristics of these 'exotic spacetimes,' we also explore other non-trivial general relativistic geometries that generate closed timelike curves. |
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Giovanni LOSURDO Parallel Session: GW7 - Ground-based detectors: from second to third generationm Description: The session will have two main focuses: 1. the evolution of the current GW network through the planned upgrades of LIGO and Virgo and the addition of new detectors (Kagra, LIGO India); 2. the effort being pursued in Europe and US towards 3G detectors (Einstein Telescope, Cosmic Explorer). |
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Orlando LUONGO Parallel Session: AT7 - Theories of gravity: alternatives to the cosmological and particle standard models Description: In the standard model of cosmology, the ΛCDM model based on Einstein’s General Relativity, dark energy is introduced completely ad hoc in order to explain the present acceleration of the universe. The model requires also the introduction of dark matter dominating (by far) ordinary baryonic matter but yet undetected in the laboratory, and it suffers from astrophysical problems. Modifying gravity is a possible alternative, and many such proposals have been presented in recent years. Likewise, the standard model of particle physics is unable to incorporate all the current particle phenomenology and proposed dark matter candidates. Cosmology and particle physics come together in the early universe and, surprisingly, also in theories and models of the present, accelerating universe. This session is formulated in a wide framework to include several topics related to these problems, and spanning alternative theories of gravity and cosmology, alternatives to the ΛCDM model, quantum field theory applied to gravity, extensions of the standard model of particle physics, and dark energy and dark matter from a particle physics point of view. This session represents the interplay between, and the efforts to match, particle physics and cosmology, giving particular emphasis to the role played by particle quantum field theory in the early and the late universe. |
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Alfredo MACIAS Parallel Session: BS2 - Scalar fields in cosmology Description: In the last years, the scalar field is becoming an interesting field of study in Cosmology and Astrophysics. It appears in the formulation of many phenomena in gravitational theories. Scalar fields occur throughout physics, as spin--zero quantum fields. A scalar field is always present in the context of Dirac's large number hypothesis and also in all unified field theories; it appears as a possible type of matter, i.e., as dilatons and as inflatons in the early periods of the Universe, as a candidate to describe the dark matter nature, and as a possible Bose-Einstein condensates. The purpose of this session is to discuss different bosonic systems, scalar fields, appearing in Cosmology and Astrophysics. |
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Keiichi MAEDA Parallel Session: BN4 - End of white dwarfs and type Ia supernova Description: The nature of progenitors of type Ia Supernovae (SNe Ia) has not yet been clarified. With rapidly increasing observational data and new theoretical ideas, there is an emerging picture that they may indeed consist of a mixture of different evolutionary pathways, including the accreting white dwarfs (WDs) either with the Chandrasekhar mass or sub-Chandrasekhar mass, and the binary WD mergers. These systems are linked to various astrophysical phenomena in which a WD is involved. The session aims at stimulating discussion on these links, especially between the accreting WDs and SNe Ia: (1) SN Ia progenitor evolution scenarios, (2) SN Ia explosions and their remnants, (3) accreting WS systems and related transients at various wavelengths. |
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Manuel MALHEIRO Parallel Session: WD2 - Origin and physics of Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars Description: |
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Grant J. MATHEWS Parallel Session: GB9 - GRB 151027A and GRB 090618, the equatorial view of BdHNe Description: |
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Nikolaos MAVROMATOS Parallel Session: DM1 - Interacting Dark matter Description: The session is devoted to the physics of all possible aspects of interacting dark matter, including self interactions of dark matter and their cosmological consequences, or interactions of dark matter with ordinary matter and their consequences. Various types of dark matter in various models, including supersymmetry, are considered. Dark matter searches also constitute part of the session's subject. |
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Andrew MELATOS Parallel Session: GW1 - Sources of Gravitational Waves Description: The main aims of the session are: (1) to review recent progress in source modelling; (2) to discuss how GW detections can help solve problems in astrophysics and cosmology, e.g. binary star evolution; and (3) to explore ways in which GW signals can be combined with source models to answer fundamental questions in physics that cannot be probed easily in terrestrial laboratories, e.g. neutrino transport in ultradense environments, nuclear equation of state, origin of superstrong magnetic fields, et cetera. |
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Debora Peres MENEZES Parallel Session: NS3 - Different aspects of the QCD phase diagram investigated with hadronic models Description: This parallel session is devoted to review and discuss various aspects of the QCD phase diagram. The main focus will be on the variables of interest (temperature, density, strangeness, isospin and magnetic field) to understand liquid-gas phase transitions, transition to a deconfined phase, neutron star properties and relativistic heavy ion collisions. Topics that will be discussed include the presence of hyperons in cold and warm stellar matter, different phases of cold quark matter, the effect of the density dependence of the symmetry energy on neutron star properties and heavy ion collisions, the presence of light clusters and pasta phases in the neutron star crusts and core-collapse supernova matter. |
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Aniello MENNELLA Parallel Session: CM5 - Present and future of CMB observations Description: Observations of the cosmic microwave background (CMB) continue to offer wonderful opportunities to deepen our understanding of cosmology and fundamental physics. This session will focus on recent advances and future plans for precision measurements of the CMB. We welcome presentations of recent results and ongoing efforts to measure CMB polarization, CMB frequency spectrum, Sunyaev-Zel'dovich effect, and relevant astrophysical sources. We seek to stimulate discussion on issues related to calibration, systematic effects, and foreground components for ground-based, balloon-borne, and satellite measurements. |
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Marco MERAFINA Parallel Session: DM4 - Self Gravitating Systems and Dark Matter Description: his session is devoted to the presentation and discussion of new theoretical results regarding the analysis of the properties of the galactic halos from the gravitational point of view in connection with the dark matter particle mass problem. Exotic hypotheses including axions or particles with strangeness are also taken into account. |
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Razmik MIRZOYAN Parallel Session: HE1 - Very High Energy Gamma Rays Description: The development of the atmospheric Cherenkov imaging technique for ground-based gamma-ray astronomy has led to a rapid growth in the number of known sources and source types of Very-High-Energy (above 30 GeV) gamma rays, and to unveiling mysteries of cosmic rays. Large field-of-view instruments like HAWC are also providing new information, in particular on extreme accelerators. The future is bright: the construction of the Cherenkov Telescope Array (CTA) has started, and new instrument designs for multi-TeV detection have been proposed. Next-generation telescopes are under construction and will increase dramatically the knowledge available at this extreme end of the cosmic electromagnetic spectrum. VHE gamma-ray astronomy has a special value in the multimessenger context, i.e., in conjunction with neutrino and gravitational wave detection. |
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Sergey MOISEENKO Parallel Session: AC2 - MHD processes near compact objects Description: The topic of the parallel session includes different processes in strong gravitational fields, where a magnetic field and plasma properties play an important, and even decisive role. It includes magneto-rotational processes in supernova and supernova remnants, gamma-ray bursts and jets; processes which take place near pulsars, magnetorotational instability; structure and dynamics of accretion disks inside the ergosphere, and close to the last stable orbit of the Kerr black hole, gravitation lensing in plasma, etc. |
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Rodrigo NEGREIROS Parallel Session: NS1 - Observational Constraints on the Micro and Macroscopic Properties of Compact Stars Description: This session is devoted to the advances on the observational data regarding compact stars, and on how such data may be used to constrain the micro and macroscopic properties of such objects. The aim of this session is to present and discuss recent state of the art observational data from astrophysical phenomena and systems such as cooling-down neutron stars, X-ray bursters, low-mass X-ray binaries, QPOs, relativistic binaries, and similar. Particular focus is given to the astrophysical data leading to estimates of the mass, radius, moment of inertia, quadrupole moment, and magnetic field of neutron stars, hybrid stars, and strange quark stars. The consequences of the observational constraints on the interior equation of state of these objects constitute also a target of this session. |
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Wei-Tou NI Parallel Session: GW4 - Middle-Frequency (0.1 Hz to 10 Hz) Gravitational Wave (GW) Detection and its Sources Description: With the detection of high-frequency GWs from the coalescence of stellar-size black holes and neutron stars, we are formally ushered into the age of gravitational-wave astronomy. LISA Pathfinder (LPF) launched on 3 December 2015 has completely met the stringent LISA drag-free demand and has successfully paves the road for space detection of low frequency (0.1 Hz to 0.1 Hz) GWs and middle-frequency (0.1 Hz to 10 Hz) GWs. Talks will be focused on recent activities both for Earth-based and space borne detection of middle-frequency GWs: GW sources, Newtonian Noise Cancellation, TOBA (Torsion Bar Antenna), MIGA (Matter-wave laser Interferometric Gravitation Antenna), AIGSO (Atomic Interferometric Gravitational-wave Space Observatory), MAGIS (Mid-band Atomic Gravitational Wave Interferometric Sensor), AMIGO (Astrodynamical Middle-Frequency Interferometric Gravitational-wave Observatory), SOGRO (Superconducting Omni-directioanl Gravitational Radiation Observatory), etc |
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Hans Ulrik NØRGAARD-NIELSEN Parallel Session: CM2 - Cosmic Backgrounds from radio to far-IR Description: This parallel session will focus on the interpretation and perspectives for cosmology and astrophysics coming from cosmic backgrounds from radio to far-IR, in both temperature and polarization. While the final release and corresponding results from the Planck mission is forthcoming, sub-orbital experiments are investigating on CMB polarization anisotropies and searching for primordial gravitational waves, and future CMB missions of different scales are under study. The sub-mm / far-IR domain, crucial for high-frequency foreground mitigation, allows to study a number of astrophysical cosmology topics, including the early phases of star and galaxy formation. In parallel, on-going and future radio projects promise to shed light on the dawn ages and reionization epoch and to provide 3D images of the Universe evolution. The authors of both invited and contributed talks are encouraged to underline the connection between astrophysical and cosmological results. |
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Darío NÚÑEZ Parallel Session: BS2 - Scalar fields in cosmology Description: In the last years, the scalar field is becoming an interesting field of study in Cosmology and Astrophysics. It appears in the formulation of many phenomena in gravitational theories. Scalar fields occur throughout physics, as spin--zero quantum fields. A scalar field is always present in the context of Dirac's large number hypothesis and also in all unified field theories; it appears as a possible type of matter, i.e., as dilatons and as inflatons in the early periods of the Universe, as a candidate to describe the dark matter nature, and as a possible Bose-Einstein condensates. The purpose of this session is to discuss different bosonic systems, scalar fields, appearing in Cosmology and Astrophysics. |
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Niels OBERS Parallel Session: AT6 - Applied Newton-Cartan Geometry Description: Despite the huge success of General Relativity, recently the realization has dawned that non-relativistic gravity encapsulates much more than just Newtonian gravity. Thus, Newton-Cartan geometry can be used to describe gravity at velocities that are low with respect to the speed of light, but with strong gravitational fields. Hence non- relativistic gravity is emerging as a novel tool to get a hold on the non-perturbative properties of non-relativistic models that are otherwise difficult to access. Effective field theories in a Newton-Cartan background have been studied in condensed matter and used to describe a variety of non-relativistic systems such as the Fractional Quantum Hall effect. Parallel to this development, recent studies of non-AdS holography involving Lifshitz spacetimes have led to field theories with non-relativistic scaling, that are naturally coupled to an extension of Newton-Cartan geometry that includes torsion, with twistless torsion being a special case in which there are surfaces of absolute simultaneity. Besides the holographic and effective field theory applications, there have been a host of other recent applications of Newton-Cartan geometry in different fields ranging from hydrodynamics to modified gravity. For instance, it has been shown that Hořava-Lifshitz gravity and novel extensions can be described using dynamical Newton-Cartan geometry. The field of Applied Newton-Cartan Geometry is currently a rapidly developing field which is attracting researchers from different directions, that are inspired to contribute to uncovering the many possible interconnections and applications. |
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Paul O'BRIEN Parallel Session: GB3 - Cosmology and multi-messenger astrophysics with Gamma-Ray Bursts Description: |
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Paolo PADOVANI Parallel Session: HE5 - Neutrino Astronomy Description: After a time in which only TWO neutrino sources were known (the Sun and SN 1987A) we are now entering a new era in which the first associations between neutrino and electromagnetic sources are being made. This session would like to focus on the status of neutrino astronomy from the observational, theoretical, and population points of view by reviewing: - results from neutrino experiments; - status of the identification of the astrophysical sources of neutrinos; - classes of most likely emitters; - theoretical perspective; - the way forward. |
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Aurora PEREZ MARTINEZ Parallel Session: NS2 - New States of Matter in the Universe – From quarks to the Cosmos Description: Our understanding of the origin of the Universe, of its evolution and the physical laws that govern its behavior, as well as on the different states of matter that makes up its evolutionary stage, reached in recent years levels never before imagined. This is due mainly to the new and recent discoveries and scientific developments in astronomy and relativistic astrophysics, as well as, to the experiments on particle and nuclear physics that made the traditional boundaries of knowledge on physics to be overcome. As a result, we have presently a new understanding about the Universe in its two extreme domains, the very large and the very small: the recognition of the deep connection that exists between quarks and the Cosmos. The parallel session will focus this way on the following topics: astroparticle physics, cosmology, gravitation, field theory, nuclear physics, black holes, neutron stars and white dwarfs as tests of general relativity on the strong gravity domain, heavy ion collisions and the formation of the quark-gluon plasma in the early Universe, quark stars and magnetars, dark matter and dark energy, strong magnetic fields in compact stars and in the Universe, the cosmic microwave background, and topics related to these. |
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Volker PERLICK Parallel Session: PT2 - Gravitational lensing and shadows Description: This session is devoted to theoretical studies of gravitational lensing, including numerical modelling. Emphasis is expected to be on analytical and numerical studies of lensing by black holes and other compact objects (in particular on shadows, on higher-order images and on the influence of a plasma) but talks on other aspects of light propagation in gravitational fields are welcome as well. |
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Roberto PERON Parallel Session: PT5 - Testing gravitation theories in space Description: The session deals with the recent advances in testing general relativity and alternative theories of gravitation in the particular environment given by space. This includes tests performed around Earth with space geodesy techniques such as Satellite Laser Ranging, in deep space with interplanetary probes and the ongoing efforts for measuring gravitational waves with constellations of orbiting spacecraft. With the advance of experimental techniques, the need for a proper interpretation in a relativistic setting of the experimental data is becoming more and more pervasive: hence contributions in the context of relativistic geodesy, relativistic astrometry and relativistic metrology in general are welcome. Also welcome are dedicated contributions on foundational topics, e.g. tests of the Equivalence Principle. |
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David POLARSKI Parallel Session: DE1 - Dark Energy and the accelerating universe Description: This parallel session will be devoted to the study of the nature and the physical properties of Dark Energy producing the observed accelerated expansion of the present Universe. It will cover the phenomenological reconstruction of dark energy properties from observations, as well as consideration of a wide variety of theoretical models and approaches aimed to explain existing observational data, including modified gravity models and those with an interplay between dark energy and dark matter. |
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Andy POLLOCK Parallel Session: HE8 - Astronomical Data in the Multi-messenger era Description: Much has been done in recent years, especially in space astronomy, to offer open access, interoperable platforms and data services, demonstrating how natural is the evolution towards a more transparent and inclusive ecosystem of tools and services for the data-intensive astronomy of the near-future. Further efforts are nevertheless still necessary to consolidate, standardise and expand services in the current era of multi-band / multi-messenger astronomy, and in order to optimise the utility of the data services that form the fundamental interface between theoretical and observational astrophysics. This session wishes to focus on the status of astronomical data services and initiatives, and on current paradigms in astronomical data processing which aim to promote a significant data-driven surge in training, education and scientific discovery. A special focus is set towards new proposals to deal with emerging issues in the future of big-data astronomy, and on efforts in the framework of the Open Universe initiative. |
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Constança PROVIDÊNCIA Parallel Session: NS3 - Different aspects of the QCD phase diagram investigated with hadronic models Description: This parallel session is devoted to review and discuss various aspects of the QCD phase diagram. The main focus will be on the variables of interest (temperature, density, strangeness, isospin and magnetic field) to understand liquid-gas phase transitions, transition to a deconfined phase, neutron star properties and relativistic heavy ion collisions. Topics that will be discussed include the presence of hyperons in cold and warm stellar matter, different phases of cold quark matter, the effect of the density dependence of the symmetry energy on neutron star properties and heavy ion collisions, the presence of light clusters and pasta phases in the neutron star crusts and core-collapse supernova matter. |
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Andrea POSSENTI Parallel Session: NS4 - Pulsars' methodology for fundamental physics Description: The combination of evolutionary reasons and intrinsic properties allow some radio pulsars to behave as highly stable clocks. Via a methodology dubbed pulsar timing, the measurement of the times of arrival of their pulses can lead to accurately constraining their kinematic, rotational, positional and orbital parameters, as well as informing about the physical status of their space-time environment. That provides the basis for exploiting the pulsars as tools for several unique experiments in fundamental physics. They range from direct tests of the gravity theories in a strong field regime, to the direct detection of the gravitational waves in the nano-Hz frequency range, from the investigation of the nuclear interactions to put constraints to the fundamental constants and to the basic principles of physics. This session is aimed to report on the most recent achievements resulting from this flourishing branch of the pulsar research, on the way to the incoming experiments which will produce a new revolution in the field. |
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Jorge PULLIN Parallel Session: QG3 - Loop quantum gravity: cosmology and black holes Description: The session will cover developments in the application of loop quantum gravity to cosmology and black holes, including topics like bouncing models in loop quantum gravity/cosmology, observational effects of quantum gravity in anisotropies of the cosmic microwave background, singularity resolution and entropy in black holes, spinfoam and group field theory cosmology, among others. |
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Hernando QUEVEDO Parallel Session: BH5 - Black hole thermodynamics Description: This parallel session will be devoted to the different aspects of black hole thermodynamics. Topics of interest include, but are not limited to, thermodynamic variables, phase transitions, extended phase space, stability properties and critical coefficients of black holes in any dimension. The session will cover also the applications of different analytical and geometric methods in the study of black hole thermodynamics. |
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Gannouji RADOUANE Parallel Session: DE2 - Dark Energy and Large Scale structure Description: Talks presented in this session will focus on the formation of structures from inflation to the late accelerating universe. This session will cover the impact of different models in the non-linear regime, their effects on structure formation based on dark energy models, modified gravity, relativistic corrections to newtonian structure formation and the effect of inhomogeneous cosmological models on relativistic cosmology plus their impact on global properties of the universe.We also accept contributions to discuss the different analytical or semi-analytical formalisms to tackle the non-linear regime of structure formation often based on an effective field approach which would allow for a connexion to the modern view of inflationary physics. |
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Diego RUBIERA-GARCIA Parallel Session: AT3 - Wormholes, Energy Conditions and Time Machines Description: The General Theory of Relativity has been an extremely successful theory, with a well established experimental footing, at least for weak gravitational fields. Its predictions range from the existence of black holes, gravitational radiation to the cosmological models, predicting a primordial beginning, namely the big-bang. All these solutions have been obtained by first considering a plausible distribution of matter, and through the Einstein field equation, the spacetime metric of the geometry is determined. However, one may solve the Einstein field equation in the reverse direction, namely, one first considers an interesting and exotic spacetime metric, then finds the matter source responsible for the respective geometry. In this manner, it was found that some of these solutions possess a peculiar property, namely 'exotic matter,' involving a stress-energy tensor that violates the null energy condition. These geometries also allow closed timelike curves, with the respective causality violations. These solutions are primarily useful as 'gedanken-experiments' and as a theoretician's probe of the foundations of general relativity, and include traversable wormholes and superluminal 'warp drive' spacetimes. In this parallel session, in addition to extensively exploring interesting features, in particular, the physical properties and characteristics of these 'exotic spacetimes,' we also explore other non-trivial general relativistic geometries that generate closed timelike curves. |
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Jorge RUEDA Parallel Session: BN3 - NS-NS and NS-WD mergers Description: NS-NS mergers are at the center of high energy astrophysics and they generate some of the most spectacular phenomena; from gamma-ray bursts, to optical transients to high-frequency gravitational waves (LIGO/Virgo sources). However, much neglected NS-WD mergers can produce very similar events alas with potentially different characteristics. They can also produce gamma-ray bursts, optical transients and low-frequency gravitational waves (LISA sources). Our main focus during this session is to discuss the most recent advancements in observational and theoretical studies of NS-NS and NS-WD mergers. In particular, we would like to assess and compare these two types of mergers in context of their progenitors (stellar evolution), external environment (merger sites/host galaxies), physics of merger (general relativity/gravitational waves) and the explosive aftermath (EM counterparts). Parallel Session: NS1 - Observational Constraints on the Micro and Macroscopic Properties of Compact Stars Description: This session is devoted to the advances on the observational data regarding compact stars, and on how such data may be used to constrain the micro and macroscopic properties of such objects. The aim of this session is to present and discuss recent state of the art observational data from astrophysical phenomena and systems such as cooling-down neutron stars, X-ray bursters, low-mass X-ray binaries, QPOs, relativistic binaries, and similar. Particular focus is given to the astrophysical data leading to estimates of the mass, radius, moment of inertia, quadrupole moment, and magnetic field of neutron stars, hybrid stars, and strange quark stars. The consequences of the observational constraints on the interior equation of state of these objects constitute also a target of this session. |
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Matteo RUGGIERO Parallel Session: ED1 - Teaching Einsteinian Physics to School Students Description: Einstein played a pivotal role in the development of quantum physics, and his theory of general relativity represents our best understanding of the macroscopic Universe, describing, with great precision, the interplay between the geometry of space-time and its matter and energy content. Besides its outstanding importance for science, Einsteinian physics, encompassing quantum mechanics and relativity underpins almost all modern technology, as epitomised by the semiconductor physics and GPS navigators in smart phones. Gravitational wave detectors, which are quantum instruments for measuring spacetime can only be understood in an Einsteinian context. Despite all this, the Newtonian concepts of space, time, matter and radiation, which are in conflict with modern physics, are still taught in schools worldwide. In this session we will discuss and present research findings focussed on the necessity and possibility of grounding school education in Einsteinian concepts across the years K-12. Papers are invited on all aspects of the teaching and learning of Einsteinian physics including curriculum proposals, educational research results and approaches for connecting Einsteinian concepts to important Newtonian tools. |
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Tilman SAUER Parallel Session: HR1 - History of Relativity and Cosmology Description: In this historical session, we will focus on the history of the discovery of gravitational waves, recently detected by the Ligo-Virgo collaboration, to commemorate their prediction a century ago. More generally, we will look back at the history of general relativity and some of its main contributors but also discuss papers on other topics of historical interest with a particular focus on the connections between Einstein and his theories with Italy. |
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Susan SCOTT Parallel Session: ES3 - Exact Solutions (including higher dimensions) Description: In this session we will consider physical aspects of exact solutions of Einstein's equation and higher dimensional theories. This will include all issues related to the global structure of these solutions, the physical interpretation of the solutions and the analysis of their physical properties including symmetries and singularity structure. |
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Manuel ARCA SEDDA Parallel Session: GW8 - Dense stellar environments as sites of gravitational wave emission Description: Dense stellar environments (from open star clusters to nuclear star clusters) are suited environments to study compact remnants (white dwarfs, neutron star and black holes, from stellar to supermassive) either as single or multiple objects. In this session, we will present modern results of the evolution of such compact massive objects in their environment, up to their possible final mergers and associated bursts of gravitational waves. |
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Costantino SIGISMONDI Parallel Session: HR2 - Angelo Secchi and Astrophysics Description: Angelo Secchi (1818-1878) was the most relevant italian astronomer of 1800, capable to develop and spread rapidly the techniques of spectroscopy applied to the stars and to the Sun. Author of more than 770 publications, his production was seminal also in Meteorology, Idrology, Oceanography and Topography. The books on The Sun and The stars reached a vaste public maintaining the top level many decades after his death. The spectral classification of stars has in Secchi the pioneer, opening the way to the Harvard catalogues. The NASA dedicated to Secchi a special mission for the study of the Sun, which many results and publications still in progress. We will focus on the vaste scientific activity of Angelo Secchi, as well as on his social and scientific milieu. |
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Parampreet SINGH Parallel Session: QG3 - Loop quantum gravity: cosmology and black holes Description: The session will cover developments in the application of loop quantum gravity to cosmology and black holes, including topics like bouncing models in loop quantum gravity/cosmology, observational effects of quantum gravity in anisotropies of the cosmic microwave background, singularity resolution and entropy in black holes, spinfoam and group field theory cosmology, among others. |
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Reinoud Jan SLAGTER Parallel Session: CS1 - Cosmic Strings Description: Cosmic strings (CS’s) are topological defects formed at the GUT symmetry breaking scale in the Einstein-U(1) scalar- gauge field model. This model shows a surprising resemblance with superconductivity and the relativistic Nielsen-Olesen quantized magnetic flux vortex solution. In the standard model of particle physics this scalar- gauge field is responsible for the spontaneously broken symmetry (Higgs mechanism). So one could say that this quantum field with the Mexican hat potential has lived up to its reputation. In cosmological context, the confined regions of the false vacuum of the scalar field form a locus of trapped energy, i.e., a CS. The mass and dimension of a CS is largely determined by the energy scale at which the phase transition takes place. It is believed that in the FLRW model a scale-invariant cosmic string-network is formed. Observational bounds, however, predict a negligible contribution of CS’s to large-scale inhomogeneities such as the angular distribution in the CMB radiation. A renewed interest occurred when it was realized that CS’s could be produced within the framework of superstring theory inspired cosmological models, i.e., brane-world models. Supersymmetric GUT’s can even demand the existence of CS. These super-massive CS’s could be produced when the universe underwent phase transitions at energies much higher than the GUT scale, so their gravitational impact increases. Although evidence of CS are not yet found, new observational windows are opened by these super-massive CS’s. |
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Clement STAHL Parallel Session: DE2 - Dark Energy and Large Scale structure Description: Talks presented in this session will focus on the formation of structures from inflation to the late accelerating universe. This session will cover the impact of different models in the non-linear regime, their effects on structure formation based on dark energy models, modified gravity, relativistic corrections to newtonian structure formation and the effect of inhomogeneous cosmological models on relativistic cosmology plus their impact on global properties of the universe.We also accept contributions to discuss the different analytical or semi-analytical formalisms to tackle the non-linear regime of structure formation often based on an effective field approach which would allow for a connexion to the modern view of inflationary physics. |
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Joan SOLÀ PERACAULA Parallel Session: CM4 - Tensions on LCDM cosmological model and model-independent constraints Description: This session will be devoted to study the ability of the LCDM model (the "concordance model" of cosmology) to describe the modern cosmological observations and compare with model-independent analyses as well as with a variety of alternative theoretical frameworks (in particular dynamical dark energy models of different kinds) which have been proposed to describe the same set of observations. Among the hot subjects that should be discussed in this session we have e.g. i) The discordant measurements between the Hubble parameter determination from the CMB data and the distance ladder measurements, ii) The long standing mismatch between the geometry and structure formation data, in particular the sigma_8 tension, a quantity whose value in the LCDM is predicted to be larger than what is needed to improve the adjustment of the structure formation data obtained from redshift space distortions and other methods, and iii) The need to analyse data in a model independent way. Discussions are also necessary concerning possible unaccounted systematic effects. |
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Yevgeny STADNIK Parallel Session: PT4 - Variation of the fundamental constants, violation of the fundamental symmetries and dark matter Description: Search for the space-time variation of the fundamental constants is a very broad research area based on numerous astrophysical and geophysical observations and laboratory experiments. Recent results show that this is also a very efficient method to search for low-mass dark matter. Traditional searches for the scattering of dark-matter particles off nuclei have not yet produced a strong positive result. The challenge with such traditional searches is that they look for effects that are fourth power in a very small interaction constant. However, there are effects of dark matter that are first power in the interaction constant, which may give an enormous advantage. Low-mass bosonic dark-matter particles produced after the Big Bang form an oscillating classical field and/or topological defects. Various non-gravitational interactions of ordinary matter with these fields can produce a cosmological evolution of the fundamental constants, such as the strengths of the fundamental forces (including electromagnetism), as well as the masses of particles. Variations in these physical constants leave characteristic fingerprints on physical processes that take place from as early as a second after the birth of the Universe until the present day. Effects of varying physical constants include changes in the primordial abundances of light elements, cosmic microwave background fluctuations, quasar absorption spectra and pulsar timing. Further progress may be achieved using atomic clocks, laser-interferometry experiments (such as LIGO, which has detected gravitational waves), optical cavities and other laboratory devices. Other effects of dark matter include oscillating spin-precession effects, oscillating parity-violating effects and oscillating electric dipole moments. The first results of observations, which have improved the sensitivity to the interaction of dark matter with the photon, electron, nucleons, quarks, gluons, Higgs boson, W and Z bosons by up to 15 orders of magnitude, have already been published. Astrophysical observations indicate that 85% of the matter content in the Universe is due to dark matter, the identity and properties of which remain a mystery. Traditional searches for the scattering of dark matter articles off nuclei have not yet produced a strong positive result. The challenge with these traditional searches is that they look for effects that are fourth or second power in a very small interaction constant. However, there are effects of the first power in the interaction constants, which may give an enormous advantage. The low mass boson dark matter particles produced after Big Bang form an oscillating classical field and/or topological defects. Interactions with these fields produce a cosmological evolution of the fundamental constants such as the strength of the fundamental forces (including electromagnetism), as well as the masses of the particles. Variations in these physical constants leave characteristic fingerprints on physical processes that take place from as early as a second after the birth of the Universe until the present day. The effects include change of the primordial abundances of light elements, cosmic microwave background fluctuations, quasar spectra and pulsar timing. Further progress may be achieved using atomic clocks, laser interferometry experiments (such LIGO which detected gravitational waves), silicon cavities and other laboratory devices. Other effects of dark matter include oscillating spin-precession, oscillating parity violating effect and oscillating electric dipole moments. First results of the observations which improved sensitivity to interaction of dark matter with photon, electron, quarks, Higgs, W and Z boson by up to 15 orders of magnitude have already been published. |
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Alexei STAROBINSKY Parallel Session: DE1 - Dark Energy and the accelerating universe Description: This parallel session will be devoted to the study of the nature and the physical properties of Dark Energy producing the observed accelerated expansion of the present Universe. It will cover the phenomenological reconstruction of dark energy properties from observations, as well as consideration of a wide variety of theoretical models and approaches aimed to explain existing observational data, including modified gravity models and those with an interplay between dark energy and dark matter. |
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Jeff STEINHAUER Parallel Session: BH8 - Hawking radiation in analogue black-holes Description: Analogue black holes are Earth-based experiments with metrics similar to those of real black holes. They allow for the verification of Hawking's calculation regarding the emission of Hawking radiation. This is particularly useful since the observation of Hawking radiation from a real black hole seems very difficult. Both the experiments and the theoretical studies have given insights into real black holes. The session will focus on the theoretical predictions, as well as the observation of Hawking radiation. |
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Jan STEINHOFF Parallel Session: BH9 - Gravitational interaction of n-pole point particles and higher-spin fields Description: Understanding the dynamics of test bodies/test fields with n-polar structure within special solutions of the Einstein's field equations like black holes is a hot topic in General Relativity today. While the case of dipolar particles (described either by the classic Mathisson-Papapetrou-Dixon model or by a Hamitonian) is well studied and the results are satisfying enough, the case of bodies with quadrupolar, octupolar (and beyond) structure is poorly investigated because of the various underlying difficulties. We encourage talks from a classical general relativity point of view, from a Hamiltonian point of view, from the effective-field-theory point of view, from the scattering amplitude, showing exact, approximated as well as fully numerical results, with the aim of facilitating communications among researchers in different areas and working with different techniques. We are especially open to accept talks introducing new techniques, as in the effective-field-theory and scattering amplitude context, which might offer computational advance with respect to the more traditional ones. There will be both review talks as well as contributed talks, time span of which will depend on the number of speakers. |
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Yukikatsu TERADA Parallel Session: BN4 - End of white dwarfs and type Ia supernova Description: The nature of progenitors of type Ia Supernovae (SNe Ia) has not yet been clarified. With rapidly increasing observational data and new theoretical ideas, there is an emerging picture that they may indeed consist of a mixture of different evolutionary pathways, including the accreting white dwarfs (WDs) either with the Chandrasekhar mass or sub-Chandrasekhar mass, and the binary WD mergers. These systems are linked to various astrophysical phenomena in which a WD is involved. The session aims at stimulating discussion on these links, especially between the accreting WDs and SNe Ia: (1) SN Ia progenitor evolution scenarios, (2) SN Ia explosions and their remnants, (3) accreting WS systems and related transients at various wavelengths. |
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A. Shadi TAHVILDAR-ZADEH Parallel Session: AT2 - The Einstein-Infeld-Hoffmann Legacy in Mathematical Relativity Description: In their famous 1938 Annals of Mathematics paper: 'The Gravitational Equations and the Problem of Motion,' Einstein, Infeld, and Hoffmann claimed that the field equations of general relativity theory alone determine the equations of motion of matter particles, viewed as naked point-singularities in space-like slices of spacetime. Their claim was generalized to charged naked point-singularities by Infeld's student Wallace in 1941. Although non-rigorous and full of questionable assumptions, these works have become the template of many follow-up studies, in particular the computation of gravitational wave signals. Part 1 of this session draws attention to recent rigorous advances in our understanding of the classical joint initial value problem for N point-charges and their electromagnetic fields in special and general relativity. This includes a local well-posedness theorem which uses an electromagnetic vacuum law that avoids the infinity problems of the Maxwell-Lorentz field equations. Part 2 proposes a `deformation quantization' of the classical structure of part 1 inspired by Einstein's 'Führungsfeld' idea: the singularities of mildly singular general-relativistic spacetimes are guided by solutions of Dirac-type wave equations, showing that GR and QM can peacefully co-exist (in a suitable sense). Both electrons and photons will be treated in this manner. |
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Audrey TROVA Parallel Session: AC3 - Accretion discs and jets Description: Accretion disks are the systems which most closely approach compact objects and, therefore, are an ideal system to explore the strong gavity regime. The basic physical mechanism of accretion is clear, however, several open questions remain. This includes for instance the effective equation of motion for continua in strong gravitational fields, the viscosity problem, the stability on large time scales, the "feeding" of active galactic nuclei, the structure of the inner part of accretion disks, the connection between accretion disks and jets, and the impact of accretion disc observations on generalized theories of gravity or matter models. In this session we focus on the theoretical modeling of accretion in the strong gravitational field and related phenomena, including but not limited to: (i) foundations of relativistic hydrodynamics (ii) relativistic turbulence and viscosity (iii) self-gravitational and self-electromagnetic fields (iv) modeling of accretion discs, also in various spacetimes and theories (v) accretion discs and jet creation. |
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Oleg TSUPKO Parallel Session: PT2 - Gravitational lensing and shadows Description: This session is devoted to theoretical studies of gravitational lensing, including numerical modelling. Emphasis is expected to be on analytical and numerical studies of lensing by black holes and other compact objects (in particular on shadows, on higher-order images and on the influence of a plasma) but talks on other aspects of light propagation in gravitational fields are welcome as well. |
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Gregory VERESHCHAGIN Parallel Session: GB4 - Photospheric emission in GRBs Description: Early models of cosmological gamma-ray bursts predicted the observed spectrum to be nearly blackbody. Observations were at odds with this prediction, and different theoretical models assuming optically thin emission have been put forward. However, models of such non thermal emission appear to be inconsistent with observations of steep spectra in early phases of many gamma-ray bursts. Instead models involving photospheric emission producing modified blackbody spectra explain such observed spectra quite naturally. We will discuss physical aspects of photospheric emission in relativistic outflows and cocoons, as well as observational issues related to the detection of such a photospheric component in GRBs. Special attention will be given to sub-photospheric dissipation mechanisms, geometric and dynamical effects, jet content, and presence of additional emission mechanisms. |
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Francesco VESPE Parallel Session: PT5 - Testing gravitation theories in space Description: The session deals with the recent advances in testing general relativity and alternative theories of gravitation in the particular environment given by space. This includes tests performed around Earth with space geodesy techniques such as Satellite Laser Ranging, in deep space with interplanetary probes and the ongoing efforts for measuring gravitational waves with constellations of orbiting spacecraft. With the advance of experimental techniques, the need for a proper interpretation in a relativistic setting of the experimental data is becoming more and more pervasive: hence contributions in the context of relativistic geodesy, relativistic astrometry and relativistic metrology in general are welcome. Also welcome are dedicated contributions on foundational topics, e.g. tests of the Equivalence Principle. |
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Michael VOLKOV Parallel Session: AT4 - Massive gravity, Horndeski theory and other "ghost-free" models of modified gravity Description: This section will focus on theoretical aspects of the "ghost-free" models of modified gravity. These are, for example, theories with massive gravitons recently attracted a lot of attention after the discovery of their versions free of the Boulware-Deser ghost -- the ghost-free massive gravity and bigravity. Related to them are the Galileon models obtained in the decoupling limit and, more generally, the Horndeski theories and their extensions free of the Ostrogradsky ghost. Such theories are interesting since the absence of the ghost is the necessary (although not sufficient) condition for stability, hence they may potentially provide a description of the Dark Energy and/or Dark Matter. Their various aspects may be discussed, as for example their Hamiltonian formulation and constraints; the causality and Cauchy problem; classical solutions and their stability -- black holes, stars; radiation; cosmologies; observational constraints; quantum aspects, etc. |
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Yu WANG Parallel Session: GB8 - GRB 130427A, 160509A, 160625B, The Polar View of BdHNe Morphology Description: |
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Marcus WERNER Parallel Session: AT5 - Constructive gravity Description: Constructive gravity exploits the assumption of a common canonical evolution of matter fields and their geometric background. In consequence, causality and energy conditions on given matter dynamics turn out to constrain the background so severely that the gravitational Lagrangian can be derived constructively. In this parallel session, we will review the approach, present results for the first derived, predictive gravity theory beyond general relativity, and discuss general spacetime kinematics beyond metric geometry (e.g. premetric, area metric and Finsler structures) as well as possible signatures for future observational tests. |
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She-Sheng XUE Parallel Session: SF1 - Strong (EM) Fields Physics and Laboratory Astrophysics Description: Strong electromagnetic and gravitational fields are two of the most important ingredients for astrophysics and cosmology. This session is dedicated to all theoretical aspects of high field and/or energetic phenomena due to strong electromagnetic fields and/or gravity in ground laboratories as well as astrophysics and cosmology, such asSchwinger pair creation and back-reaction,charged particle acceleration, and vacuum polarization and nonlinearity of strong electromagnetic fields and magnetogenesis. It is also dedicated to experimental and theoretical aspects of laboratory astrophysics and astrophysical observations related to strong field physics, such as intense lasers plasma acceleration, plasma interaction with strong electromagnetic fields, radiation from accelerating charges, observation of birefringence in neutron stars, simulation of strong gravity effects etc. Parallel Session: GB11 - Plasma acceleration and transparency in GRBs Description: In this parallel session we discuss the hydrodynamic evolution of the baryon-loaded plasma of photons and electron-positron pairs (fireshell) in the following aspects: (1) The conservation of total energy (thermal energy plus kinetic energy) in the ultra relativistic expansion of the plasma up to the transparency point. The thermal energy is then emitted accounting for the observed thermal component of the P-GRB, while the kinetic energy continually drives the fireshell accounting for later emission processes after the P-GRB. (2) Using observed data of thermal P-GRB emission energy, temperature, and width, as well as total emission energy, to infer the baryon load and the Lorentz gamma factor of the fireshell. These studies bring insight into the properties of baryon-loaded plasma acceleration and transparency in GRBs. |
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Alexander ZAKHAROV Parallel Session: BH2 - Theoretical and observational studies of astrophysical black holes Description: The session is devoted to theoretical and observational studies of astrophysical black holes. The session will include discussions of theoretical models for black hole solutions existing in GR and in alternative theories of gravity. Strong gravity effects and opportunities to test theoretical predictions with current and future observational facilities such as GRAVITY, The Event Horizon Telescope, JWST, E-ELT and TMT will be discussed. The main goal of the session is to establish an effective interaction between observers and theorists working in black hole astrophysics to test GR in a strong gravitational field limit and constrain alternative theories of gravity with current and future observations of astrophysical black holes. |
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Cesar Augusto VASCONCELLOS ZEN Parallel Session: NS2 - New States of Matter in the Universe – From quarks to the Cosmos Description: Our understanding of the origin of the Universe, of its evolution and the physical laws that govern its behavior, as well as on the different states of matter that makes up its evolutionary stage, reached in recent years levels never before imagined. This is due mainly to the new and recent discoveries and scientific developments in astronomy and relativistic astrophysics, as well as, to the experiments on particle and nuclear physics that made the traditional boundaries of knowledge on physics to be overcome. As a result, we have presently a new understanding about the Universe in its two extreme domains, the very large and the very small: the recognition of the deep connection that exists between quarks and the Cosmos. The parallel session will focus this way on the following topics: astroparticle physics, cosmology, gravitation, field theory, nuclear physics, black holes, neutron stars and white dwarfs as tests of general relativity on the strong gravity domain, heavy ion collisions and the formation of the quark-gluon plasma in the early Universe, quark stars and magnetars, dark matter and dark energy, strong magnetic fields in compact stars and in the Universe, the cosmic microwave background, and topics related to these. |
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Bing ZHANG Parallel Session: GB1 - Fast radio bursts: observations, ideas and prospects Description: This session will include invited talks and contributed talks to discuss the current observational progress, theoretical ideas, as well as future perspectives in the study of fast radio bursts, a new type of cosmological transients whose nature is currently unknown. |
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Binbin ZHANG Parallel Session: GB8 - GRB 130427A, 160509A, 160625B, The Polar View of BdHNe Morphology Description: |
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Shu ZHANG Parallel Session: HE3 - The first Chinese X-ray astronomy mission Insight-HXMT at MGXV Description: The session will be devoted to present the first scientific results obtained with the Insight-HXMT mission. Insight-HXMT is the first Chinese space X-ray telescope satellite jointly funded by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS), and successfully launched on 15 June 2017. The payload includes large area instruments that cover a very broad energy band (1-300 keV). The active shielding of the high energy instrument (HE) is also exploited as a Gamma-Ray Burst Monitor, with a passband from 200 to 800 keV in the regular mode, and from 200 keV to 2 MeV in the GRB mode. |