Invited Speakers
 
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Abhay ASHTEKAR TALK: Recent Conceptual and Phenomenological Advances in Loop Quantum Gravity ABSTRACT: I will provide a few highlights of recent results in loop quantum gravity that address some of the long standing questions regarding the very early universe and quantum properties of black holes 
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Zvi BERN TALK: Ultraviolet surprises in quantum gravity ABSTRACT:
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Rita BERNABEI TALK: Direct detection of Dark Matter particles ABSTRACT: The present status of direct detection of Dark Matter (DM) particles will be summarized, with particular care to the DAMA model-independent DM annual modulation results. Arguments on comparisons will be addressed showing that there is large room for compatibility between positive signals and negative hints, considering both the different adopted procedures and techniques, the different experimental observables, the different exposures, the existing experimental and theoretical uncertainties and the widely open scenarios for astrophysical, particle and nuclear Physics aspects. Recent results on diurnal investigation will also be introduced. Realistic experimental perspectives will be, finally, addressed with attention to some particular cases.
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Marco BERSANELLI TALK: The astrophysical results of the Low Frequency Instrument of Planck satellite ABSTRACT: The two talks of Bersanelli and Puget are conceived as complementary to each other. To first order, the first talk will cover Instruments, systematics, calibration; frequency maps in Temperature and Polarisation; Component separation (CMB map and astrophysical components); CMB power spectra (T and P); gravitational lensing: map and spectrum; likelihood. The second one will cover cosmological parameters, non-Gaussianity; SZ effect from Planck, Galactic astrophysics; interstellar dust (T and P); Polarized foregrounds; Planck/Bicep2 anlysis.
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Mihalis DAFERMOS TALK: Black Hole physics ABSTRACT: |
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Thibault DAMOUR TALK: Gravitational Radiation and the Problem of Motion: A Centenary Assessment ABSTRACT: A network of ground-based interferometric gravitational wave detectors (LIGO/Virgo/...) is currently being upgraded, and should, in a few years, reach a sensitivity enabling them to detect the gravitational waves emitted by coalescing compact binaries: i.e. binary systems made of black holes and/or neutron stars. This prospect has motivated renewed theoretical studies of the motion and radiation of relativistic two-body systems. I will review both the history of the general relativistic problem of motion, and the recent analytical studies of (comparable-mass) two-body systems. The comparison of analytical results to numerical relativity results will also be discussed. Particular attention will be given to the recently developed "Effective One Body" approach to the motion and radiation of binary systems.
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Paolo DE BERNARDIS TALK: ABSTRACT: |
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John ELLIS TALK: No-Scale Inflation: a Bridge between String Theory and Particle Physics? ABSTRACT:
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Francis EVERITT TALK: Overview and Completion of Gravity Probe B ABSTRACT:
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Sergio FERRARA TALK: Supersymmetry and Inflation ABSTRACT: Theories with elementary scalar degrees of freedom seem nowadays to be required for simple descriptions of the Standard Model of fundamental particle interactions and of the early evolution of the Universe. A space-time symmetry, consistent with Relativistic Quantum Field Theory, which naturally accommodates scalar fields is Supersymmetry, and supersymmetric extensions of the Standard Model with their predictions are under scrutiny at the Large Hadron Collider (LHC). It is then natural to embed theories of inflation in the Supergravity context, also in view a possible ultraviolet completion in SuperString Theory. After a brief description of the general framework of inflation in Supergravity, minimal models for inflaton dynamics which are compatible with recent observations from PLANCK and BICEP experiments are presented, and different scenarios of Supersymmetry Breaking during and after inflation will be discussed
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Katherine FREESE TALK: Dark Matter in the Universe ABSTRACT:
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Chris L. FRYER TALK: Using Observations to Constrain the GRB Engine: Lessons from Core-Collapse Supernovae ABSTRACT: Observations of gamma-ray bursts in the past decade of produced a fast-growing database studying these objects. However, despite this broad wavelength data ranging from radio to gamma-rays, the progenitors, engines and emission mechanisms for these outbursts remains a matter of debate. The field of gamma-ray bursts is entering a new era, where methodical studies are replacing the fast-paced discovery-period. These new studies can bring new life to the wealth of data on these cosmic explosions, but a methodical approach means that the theoretical uncertainties must be understood to truly leverage this data. Here, the gamma-ray burst field can take advantage of the lessons learned from supernova studies. For supernovae, both broad class features and specific objects constrain our understanding of the explosion mechanism, and I will use the connection between supernova observations and theory as an example for the next steps in gamma-ray bursts. I will demonstrate how we can use current gamma-ray burst observations to constrain proposed scenarios for both progenitors and engines.
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Neil GEHRELS TALK: Explosions Throughout the Universe ABSTRACT: The gamma-ray sky is dynamic with sources transient or variable on time scales from seconds to months. These include gamma-ray bursts, supernovae, and black hole accretors, all characterized by bursts and flares. We are in a rich period of time domain astronomy with Swift and Fermi operating. The X-ray through high energy gamma-ray skies are being monitored at sensitivities more than an order of magnitude better than previous experiments. The talk will highlight exciting and often surprising recent discoveries, such as tidal disruption events with stars torn apart by the gravitational shear of a massive black hole and short gamma-ray bursts that are caused by the compact object mergers that will likely dominate future gravitational wave detections.
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Stefan GILLESSEN TALK: The Galactic Center: A stellar Ballet and a gaseous Scherzo ABSTRACT: The Galactic Center is a unique astrophysical laboratory. Due to its proximity, we can observe in unparalleled detail the interaction of the massive black hole with its stellar and gaseous environment. Adaptive Optics based imaging and spectroscopy in the near-infrared have revealed about 40 individual stellar orbits, that show conclusively that the Galactic Center harbours a dark compact object of 4 million solar masses. Due to the high precision of these measurements, relativistic effects in the stellar motions will be detectable in the near future. In 2011, we discovered a compact gas cloud (â€G2â€) with roughly 3 Earth masses that is falling on a near-radial orbit toward the black hole, with a pericenter passage in 2014. Our 10-year data set beautifully shows that G2 gets tidally sheared apart during the approach. We expect that hydrodynamics will get important in the coming years, as G2 collides with the ambient gas around the black hole. If some of the cloud’s material will fall into the black hole, this might be a unique opportunity to observe how gas feeds a massive black hole in a galactic nucleus.
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Paolo GIOMMI TALK: Multi-frequency and Multi-messenger Astrophysics With Blazars: Recent Results and Predictions for Future Observations with VHE gamma-ray and Neutrino Detectors ABSTRACT: I will present some recent multi-frequency and time domain observations of blazars, the only type of extragalactic sources capable of emitting radiation across the entire electromagnetic spectrum, and possibly beyond, through other channels. Blazars are the most powerful and most energetic cosmic accelerators known, so particular attention will be given to the X-ray, gamma-ray and VHE energy bands. In particular, the number of blazar expected to be found in upcoming and mid-term future VHE observations (e.g. Fermi and CTA) will be estimated together with their contribution to the extragalactic backgrounds. Finally, I will describe some recent attempts to open the field of multi-messenger astronomy. This will include the possible association of some of the most energetic blazars with IceCube neutrinos and ultra high energy cosmic rays, and an estimate of the contribution of blazars to the neutrino extragalactic background.
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Francis HALZEN TALK: IceCube and the Discovery of High-Energy Cosmic Neutrinos ABSTRACT: The IceCube project has transformed one cubic kilometer of natural Antarctic ice into a neutrino detector. The instrument detects more than 100,000 neutrinos per year in the GeV to PeV energy range. Among those, we have recently isolated a flux of high-energy cosmic neutrinos. I will discuss the instrument, the analysis of the data, and the significance of the discovery of cosmic neutrinos. The observed cosmic neutrino flux implies that a significant fraction of the energy in the non-thermal universe, powered by the gravitational energy of compact objects from neutron stars to supermassive black holes, is generated by accelerating protons and not just electrons.
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Fiona HARRISON TALK: From Extremes of Black Hole Accretion to Exploding Stars: The Universe Through High Energy X-ray Eyes ABSTRACT: The Nuclear Spectroscopic Telescope Array (NuSTAR) has opened the high energy sky to sensitive study. In compact objects, insights gained by NuSTAR range from measurements of black hole spin, probing the innermost regions in active galaxies to discovering the most extreme accreting neutron stars. NuSTAR has also made fundamental measurements that constrain the mechanisms that explode massive stars. This talk will highlight the most fundamental advances and discoveries related to extremes of accretion and stellar collapse from the NuSTAR mission to-date. |
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Stephen HAWKING TALK: Fire in the Equations ABSTRACT:
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Werner HOFMANN TALK: Perspectives from CTA in Relativistic Astrophysics ABSTRACT: In the last decade, very high energy (VHE) gamma ray astronomy - at photon energies of 100 GeV and beyond - has developed in giant steps, with the number of known cosmic VHE gamma ray sources now well over 100. Cosmic particle accelerators – giving rise to gamma ray production when accelerated particles interact with the ambient medium and radiation fields – are ubiquitous in the Galaxy and in the Universe. Yet many questions remain open, such as: Can particle acceleration in supernova remnants quantitatively account for the observed spectrum of cosmic rays? What are the exact mechanisms of acceleration in the vicinity of compact objects such as pulsars or black holes? How do the accelerated particles influence their environment and cosmic evolution? Very high energy gamma ray astronomy also offers windows onto key questions of fundamental physics, such as the search for dark matter or the search for signs of quantum gravity inducing a dispersion in the propagation speed of very high energy photons. Current instruments are not quite sensitive enough to probe these issues, which are driving the design of the Cherenkov Telescope Array (CTA) as a next-generation facility for ground-based gamma-ray astronomy. CTA is a world-wide project, with over 1000 scientists in 29 countries working on the design of the instrument and the planning of the science programme. CTA is planned to include a northern and a southern site, equipped with arrays of Cherenkov telescopes of three different sizes, covering the energy range from 20 GeV to several 100 TeV, and providing almost an order of magnitude sensitivity increase over existing instruments. For the first time in this field, CTA will be operated as an open observatory. The presentation will review the science goals and science prospects of CTA, the performance of the instrument, and the status of design and prototyping.
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Chris HULL TALK: A review of generalized geometries in string theory ABSTRACT:
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Karl Heinz KAMPERT TALK: Ultra High Energy Cosmic Rays: What has been learned and where will we go? ABSTRACT: Measurements of the Pierre Auger Observatory and more recently also of the Telescope Array have dramatically advanced our understanding of ultra-high energy cosmic rays. The suppression of the flux around 5*10^19 eV is now confirmed without any doubt. Strong limits have been placed on the photon and neutrino components of the flux indicating that “top-down” source processes, such as the decay of superheavy particles, cannot account for a significant part of the observed particle flux. A large-scale dipole anisotropy of 4% amplitude has been found for energies above 8*10^18 eV by Auger and a flux excess over an angular scale of 20 degrees (hot-spot) has been seen in TA data above 5*10^19 eV. Particularly exciting is the observed behavior of the depth of shower maximum with energy in the Auger data which implies a gradual shift to a heavier cosmic ray composition above the ankle. Such an evolution as well as the high level of isotropy is well described by astrophysical models that describe the observed flux suppression at the highest energies in terms of cosmic ray source exhaustion, rather than by energy losses in the CMB (GZK-effect). Answering this fundamental question by measurements of the composition event-by-event into the flux suppression region is the primary goal of the upgrade of the Auger Observatory, while increasing the statistics of events is the goal of the Telescope Array upgrade. This talk will review recent results and give an outlook into the plans and challenges for the next decade and more.
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Michael KRAMER TALK: Probing gravity and fundamental physics with pulsars ABSTRACT: Radio-loud neutron stars known as pulsars allow a wide range of experimental tests for fundamental physics, ranging from the study of super-dense matter to tests of general relativity and its alternatives. As a result, pulsars provide strong-field tests of gravity, they allow for the direct detection of gravitational waves in a 'pulsar timing array', and they promise the future study of black hole properties. This talk will try to give an overview of the on-going experiments and recent results.
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Claus LAMMERZAHL TALK: Experimental gravitation ABSTRACT:
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Samir MATHUR TALK: Fuzzballs, Firewalls and all that ABSTRACT: Some 40 years ago Hawking showed that if the black hole has a smooth horizon, then information will be lost when the black hole radiates. In string theory black holes appear to have a complete set of 'hair'; these black hole states are called fuzzballs, and they radiate like normal bodies with no information loss. It was recently argued that structure at the horizon will necessarily feel like a 'firewall' to an infalling observer. We will show that this need not be the case, since one can have 'fuzzball complementarity' where an approximately smooth horizon appears as a 'dual' description.
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Viatcheslav MUKHANOV TALK: Quantum Universe ABSTRACT:
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Ken'ichi NOMOTO TALK: First Stars, Hypernovae, and Faint Supernovae in the early Universe ABSTRACT: After the Big Bang, production of heavy elements in the early universe takes place starting from the formation of the first stars, their evolution, and explosion. The nature of the first stars, first supernovae, and first black holes, however, has not been well clarified. The signature of nucleosynthesis yields of the first stars can be seen in the elemental abundance patters observed in extremely metal-poor stars, which show interesting peculiarities relative to the solar abundance pattern. I will show those peculiar pattern is related to nucleosynthesis yields of jet-induced explosions, hypernovae associated with gamma-ray bursts, and possibly superluminous supernovae in the early universe.
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Tsvi PIRAN TALK: Neutron Star Mergers, Gravitaional Waves, Gamma-Ray Bursts and the origin of Gold ABSTRACT:
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Jean-Loup PUGET TALK: The astrophysical results of the High Frequency Instrument of Planck satellite ABSTRACT: The two talks of Bersanelli and Puget are conceived as complementary to each other. To first order, the first talk will cover Instruments, systematics, calibration; frequency maps in Temperature and Polarisation; Component separation (CMB map and astrophysical components); CMB power spectra (T and P); gravitational lensing: map and spectrum; likelihood. The second one will cover cosmological parameters, non-Gaussianity; SZ effect from Planck, Galactic astrophysics; interstellar dust (T and P); Polarized foregrounds; Planck/Bicep2 anlysis.
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Martin REES TALK: How our understanding of cosmology and black holes has been revolutionised since the 1960s. ABSTRACT: 50 years ago, little was known about how our universe of stars and galaxies had emerged. Now, thanks to advances in theory and (even more) in observational techniques) we have quantitative details of cosmic evolution from the first nanosecond up to the present - and compelling (albeit speculative) models for the very earliest stages. In the same 50 years, gravitational physics has become an empirical science, and the role of black holes in high energy astrophysics has become fully recognized. This illistruate lacture will discuss these topics, and speculate on what further advances the next decades may bring.
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Katarzyna REJZNER TALK: Effective quantum gravity observables and locally covariant QFT ABSTRACT: Locally covariant QFT is a mathematically rigorous framework that allows to build models of quantum field theories on general globally hyperbolic spacetimes. Its conceptual basis relies on the algebraic approach to QFT, where a given model is specified by providing a net of algebras of local observables, associated to bounded regions of spacetimes. This point of view can be adopted also in perturbative QFT, with the use of Epstein-Glaser renormalization. These methods were recently applied in effective quantum gravity, but one has to modify the concept of observables, since they can no longer be local. In this talk I will present recent results on this subject.
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Jorge RUEDA TALK: The binary systems associated to short and long GRBs and their detectability ABSTRACT: There is increasing theoretical and observational evidence on the binary nature of the progenitors of short and long-duration gamma-ray bursts (S-GRBs and L-GRBs, respectively). For S-GRBs, possible progenitors are mergers of double neutron stars (DNSs) or NS-black hole (NS-BH) binaries. For L-GRBs, the induced gravitational collapse paradigm proposes a tight binary system composed of a carbon-oxygen (CO) core which undergoes supernova (SN) creating a massive accretion process onto a NS companion. These latter events have been called binary-driven hypernovae (BdHNe). BdHNe might lead either to a new DNS or to a NS-BH binary, the latter formed if the accretion is sufficient to bring the NS to its critical mass for the gravitational collapse to a BH. I shall discuss: 1) the role of the NS structure and the equation of state on the final fate of all the above binaries; 2) the local observed rates of these events by X and gamma-ray instruments; 3) the expected number of detections by second-generation gravitational wave (GW) detectors. I shall show that the merger of DNSs, formed in BdHNe, constitute a promising source of detectable GWs by Advanced LIGO, not accounted for in current DNS population synthesis analyses.
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Remo RUFFINI TALK: Cosmic Matrix in the Jubilee of Relativistic Astrophysics ABSTRACT:
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David H. SHOEMAKER TALK: LIGO and the network of terrestrial gravitational wave detectors ABSTRACT:
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Yakov SINAI TALK: Deterministic chaos ABSTRACT: The basic properties and examples of deterministic chaos will be explained. Some applications to astrophysics (joint work with E.Lifshits,I.Khalatnikov and others) will be outlined.
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Tracy SLATYER TALK: The Inner Galaxy Excess in Gamma-Ray Data from Fermi ABSTRACT: Studies of the inner Galaxy using public data from the Fermi Gamma-Ray Space Telescope have unveiled surprising features of the diffuse gamma-ray emission - including the giant structures known as the Fermi Bubbles, and an as-yet-unexplained excess of GeV-scale gamma-rays peaking at the Galactic Center. I will discuss the detailed characterization of this latter excess, and its possible interpretations, spanning astrophysical sources and annihilating dark matter. |
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Christian STEGMANN TALK: High energy gamma-rays ABSTRACT:
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Andrew STROMINGER TALK: Conformal Symmetry in the Sky ABSTRACT: Recent observations indicate that the sky contains black holes whose horizons are spinning at nearly the speed of light. General relativity implies that the dynamics very near the horizon of such extreme black holes is governed by an enhanced infinite-dimensional conformal symmetry - identical to the enhanced symmetry observed near the critical points of a variety of condensed matter systems. Potential observational consequences of this symmetry are explored.
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Rashid SUNYAEV TALK: Cosmic Microwave Background Radiation: In the Directions to Clusters of Galaxies, Recombination of Hydrogen in the Universe and Black-body Photosphere of our Universe ABSTRACT: I plan to describe the progress in the observations of hot gas in the clusters of galaxies producing spectral distortions of black-body spectrum of cosmic microwave background (CMB). The Planck spacecraft and the ground-based South Pole and Atacama Cosmology Telescopes discovered more than thousand rich clusters of galaxies using these spectral distortions just scanning the sky. I will tell about recombinational lines in the spectrum of CMB arising during cosmological recombinations of hydrogen and helium in the early Universe. The UV and optical lines should be shifted by cosmological redshift to radio and millimeter spectral bands. I will also describe when physical processes in the expanding Universe are able to create the observed black-body spectrum of CMB and why any energy release at redshifts higher than two million will be unobservable. In opposite,the energy release at smaller redshifts due to the dissipation of sound waves (Silk damping) should leave specific traces in the spectrum of CMB and will permit us to get information about the primordial spectrum of density fluctuations created during inflation and unobservable by other methods. The PIXIE spacecraft proposal opens a way to measure the spectral distortions connected with the sound wave dissipation, decay of unknown types of dark matter particles and other processes leading to energy release in the early Universe after a redshift of two million, i.e. when the Universe was older than a month.
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Marco TAVANI TALK: Gamma-ray Astrophysics from Space ABSTRACT:
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Gerardus 'T HOOFT TALK: Local Conformal Symmetry in Black Holes, Standard Model, and Quantum Gravity ABSTRACT: The black hole information problem and the firewall problem cause contradictions in the known laws of physics unless one assumes an extra local symmetry: conformal invariance. It must be an exact symmetry, spontaneously broken by the vacuum, in a way similar to the BEH mechanism. We note how this symmetry formally removes the horizon and the singularity inside black holes. For the Standard Model this symmetry is severely restrictive, demanding all coupling constants, masses and even the cosmological constant to be computable, in principle. Finally, this symmetry suggests that the Weyl action (the square of the Weyl curvature) should be added to the Einstein-Hilbert action. The ensuing indefinite metric states are briefly studied, and we attempt to understand the consequences by using the cellular automaton theory of quantum mechanics.
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Samuel C. C. TING TALK: The Latest Results from AMS on the International Space Station ABSTRACT: AMS is a precision particle physics spectrometer that was installed on the International Space Station in May 2011. In four years more than 65 billion cosmic ray events have been collected. A portion of the latest results will be presented.
TALK: Encounters with Modern Physics ABSTRACT: For many years I have been working on electron accelerators, proton accelerators, electron positron colliders, on the space shuttle and presently on the International Space Station. In this lecture I will attempt to summarize my experience on how to conduct experimental physics with precision results. Some of these results have helped changed our understanding of nature and produced new mysteries to explore.
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Sachiko TSURUTA TALK: Temperature of Neutron Stars ABSTRACT: Temperature of neutron stars can be estimated from thermal evolution (cooling and heating) models of isolated neutron stars as well as from accretion models of soft X-ray transients (SXT) in low mass X-ray binaries. The results obtained from these theoretical models will be compared with the latest observational data of various pulsars and SXTs. The comparison will offer some insight into the composition of the core of neutron stars, and help to answer questions such as whether it consists of neutron dominated matter only, or whether some more exotic particles such as hyperons, pion condenstates, or quarks are needed. As to magnetars, the observed surface temperature is higher than what cooling theory alone predicts and some heating mechanism is required. I will discuss possible heating mechanisms such as the internal heating from magnetic decay and the external heating from the stellar magnetosphere.
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Gabriele VENEZIANO TALK: ABSTRACT: |
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Stefano VITALE TALK: LISA Pathfinder ABSTRACT: The talk with report on the scientific objectives, the expected return and the status of LISA Pathfinder, ESA's precursor to the Gravitational Wave Observatory to be flown as the 3rd large mission of the Cosmic Vision Programme. The mission is now in its final integration stage and will be launched in October this year.
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