_E. Alesci

Title:"The full graviton propagator from loop quantum gravity"

Author: E. Alesci

Abstract: Some components of the graviton two-point function have been recently computed in the context of loop quantum gravity, using the spinfoam Barrett-Crane vertex.  We complete the calculation of the remaining components. We find that, under our assumptions, the Barrett-Crane vertex does not yield the correct long distance limit. Here we show that a vertex amplitude that depends nontrivially on the intertwiners can yield the correct limit.  We give an explicit example of asymptotic behavior of a vertex amplitude that in fact gives the full correct graviton propagator in the large distance limit.

_G. Amelino-Camelia

Title: "Quantum Gravity Phenomenology and a generalization of the Noether theorem for quantum spacetime" 

Author: G. Amellino-Camelia

Abstract: In devising a phenomenology for quantum-gravity theories additional difficulties are introduced by grey areas in our identification of observable consequences of a given theory. This has been particularly true for the study of Planck-scale modifications of spacetime symmetries, but for this I intend to argue that a recently-obtained generalization of the Noether theorem should provide a very valuable new tool.

_M. V. Battisti

  Title: "Minisuperspace dynamics in the GUP framework"

Authors: M. V. Battisti, G. Montani

Abstract: The implications of a generalized uncertainty principle are investigated in the minisuperspace context. In particular, the FRW and the Taub cosmological models are quantized by means of a modified Heisenberg algebra. Suitable wave packets are built and their motion investigated. As result of the analysis, in both the cases, the classical singularity appears to be probabilistic suppressed. Furthermore the GUP wave packets, in the Taub model, provide the right behavior in predicting an isotropic Universe.

Title: "Cosmological implication of evolutionary Quantum Gravity"

Authors: M. V. Battisti, G. Montani

Abstract: We consider a Schr\"odinger quantum dynamics for the gravitational field associated to a generic cosmological model and then we solve the corresponding eigenvalue problem. We show that, from a phenomenological point of view, an evolutionary quantum cosmology overlaps the Wheeler-DeWitt approach.

_R. Benini

Title: "Mixmaster dynamics in the Wheeler-DeWitt framework"

Authors: R. Benini, G. Montani

Abstract: In this talk we present an analysis of the Mixmaster model in the Wheeler-DeWitt framework. After a brief review of the classical evolution, several aspects of the semiclassical and of the quantum dynamics are discussed: the most important results we will present are a possible operator ordering obtained from the semi-classical analysis and the full characterization of the quantum dynamics in Misner-Chitré like variables.

_D. Bini

Title: Synchronization surfaces in black hole spacetimes

Authors: D. Bini.

Abstract: The geometry of special surfaces in black hole spacetimes is studied to select preferred spacetime slicing as well as preferred observer families, considering both the intrinsic and extrinsic properties. As "equal time surfaces"  define "synchronization surfaces," that is the set of simultaneous events  with respect to the adopted coordinate system, these foliations and their naturally associated observers play a central role in the measurement process of any physical observable quantity in the spacetime.

_:N. Carlevaro

Title: Lorentz Gauge Theory and spinor interaction

Authors: O.M. Lecian,  G. Montani, N. Carlevaro

Abstract: A gauge theory of the Lorentz group, based on the different behavior of spinors and vectors under local space time transformations, is formulated. In this gauge scheme suitable bein projections of the contortion field are identified with Lorentz connections. As a result, a propagating torsion field with the spin-current density as a source is predicted from Yang-Mills equations.

Title: On the role of viscosity in Early Cosmology

Authors: N. Carlevaro and G. Montani

Abstract: We present an analysis of  the effects induced by  dissipative processes on the evolution of the very early Universe. In particular we focus on the dynamical behavior
of a quasi-isotropic Universe in the presence of a cosmological fluid endowed with bulk viscosity. The viscosity coefficient is expressed as a power-law of the fluid energy density. Following the line of the work by E.M. Lifshitz and I.M. Khalatnikov, the Einstein and the hydrodynamical equations are integrated up to first and second order in time. As main result is shown that the quasi-isotropic solution exists only for particular values of the bulk viscosity coefficient. By requiring that the viscosity parameter be under its critical value the evolution, toward the singularity, is damped until remaining constant.

_F. Cianfrani

Title: E.C.G. Stueckelberg, a forerunner of modern physics II

Authors: F. Cianfrani, O. M. Lecian

Abstract: We will investigate some aspects of S.'s work, which have contributed to the development of modern physics.On the one hand, the ''multi-time'' formalism will be reviewed, and its application in the very first papers by Tomonaga and Schwinger will be illustrated.  

Title: The role of the time gauge in the 2nd order formalism

Authors: F. Cianfrani, G. Montani

Abstract: We perform a canonical quantization of gravity in a second-order formulation, taking as configuration variables those describing a 4-bein, not adapted to the space-time splitting. We outline how, neither if we fix the Lorentz frame before quantizing, nor if we perform no gauge fixing at all, is invariance under boost transformations affected by the quantization.

Title: Curvature-spin coupling from the semi-classical limit of the Dirac equation

Authors: F. Cianfrani, G. Montani

Abstract: The notion of a classical particle is inferred from Dirac quantum fields on a curved space-time, by an eikonal approximation and a localization hypothesis for amplitudes. This procedure allows to define a semi-classical version of the spin-tensor from internal quantum degrees of freedom, which has a Papapetrou-like coupling with the curvature. Nevertheless additional contributions to the dynamics are present, such that it differs from a that of a classical spinning body.

Title: Elementary particle interaction from a Kaluza-Klein scheme

Authors: F. Cianfrani, G. Montani

Abstract: We discuss properties of particles and fields in a multi-dimensional space-time, where the geometrization of gauge interactions can be performed For what concern spinors, we outline how the gauge coupling can be recognized by a proper dependence on extra-coordinates and by the dimensional reduction procedure. Finally applications to the Electro-Weak model are presented.

_A. Geralico

Title: Perturbations of a Reissner-Nordstr\"om black hole by a charged massive particle at rest

Authors: D. Bini, A. Geralico, R. Ruffini

Abstract: A new perturbative solution describing a two-body system consisting of a Reissner-Nordstr\"om black hole and a charged massive particle at rest is presented. The general properties of the perturbed metric, completely reconstructed analytically, are discussed. The perturbed electromagnetic field is also analyzed by plotting the associated lines of force.

_V. Lacquaniti   

Title: Matter coupling in Kaluza Klein 5D model

Authors: V. Lacquaniti, G. Montani  

Abstract: A longstanding problem in KK model is the coupling with matter. By dimensional reduction of the geodesic motion for a 5D free test particle we are able to formally restores electrodynamics, but the reduced 4D particle shows a charge over mass ratio bounded by below in such a way that it cannot fit with any kind of elementary particle. We present a criticism against 5D geodesic approach and face the hyphotesis that in KK space the geodesic motion does not deal with the dynamics of our test particle. We present a new approach, based on Papapetrou multipole expansion of the 5D matter tensor. Within this framework we deal rigorously with definitions of charge and mass and we prove that 5D dynamical equation differs from 5D geodesic equation. We find a new equation for motion that shows right coupling terms and matches with phenomenology, no boundig arising for charge and mass. Applications and perspectives of these new equations are discussed.

_O. M. Lecian

Title: E.C.G. Stueckelberg, a forerunner of modern physics II

Authors: F. Cianfrani, O. M. Lecian

Abstract: We will investigate some aspects of S.'s work, which have contributed to the development of modern physics.On the one hand, the ''multi-time'' formalism will be reviewed, and its application in the very first papers by Tomonaga and Schwinger will be illustrated.

Title: Exponential Lagrangian for the gravitational field and the problem of vacuum energy

Authors: O. M. Lecian, G. Montani

Abstract: The features of an exponential Lagrangian density for the graitational field will be analyzed in both Jordan and Einstein frame. This choice of the Lagrangian density will be explained to entail a mechanism, according to which the so-called Dark Enenrgy can be obtained from a cancellation of the vacuum energy.

Title: Extended fundamental space-time symmetries

Authors: O. M. Lecian, G. Montani

Abstract: The particle-finiteness assumption will be considered from both phenomenological and theoretical points of view. Novel schemes in theoerticalphysics will be explained to fit the truncation of KK towers. 

_E. Magliaro   

Title: "Comparing Loop Quantum Gravity with the linearized theory"

Authors: E. Magliaro, C. Perini

Abstract: In the first part of the talk E.M. will illustrate the conceptual scenario of the general boundary formulation for field theories and will present a brief description of the calculus of graviton propagator performed by E. Bianchi, L. Modesto, C. Rovelli e S. Speziale in the context of LQG.
In the second part C.P. will analyze the possibility of comparing this result with the graviton propagator in perturbative quantum gravity. For this purpose he will present the result of a recent work that demonstrates the compatibility of harmonic and radial gauge; it allows to simultaneously impose both gauges and to obtain an expression for the propagator comparable with the one provided by LQG.

_I. Milillo

Title: On the coupling between spinning particles and cosmological gravitational waves

Authors: Giovanni Montani, Irene Milillo, Massimiliano Lattanzi

Abstract : We study the influence of spin on the dynamic concerning thermal equilibrium of primordial universe. We consider a fluid of particles satisfying the Papapetrou equations and we calculate how the spin-metric terms change the evolution of the distribution function through the Boltzmann equation. In an homogeneous and isotropic space the Boltzmann equation remains unalterated and so we study the problem in a perturbative way considering the coupling with gravitational waves.

_G. Montani 

Title: Sincrhonous Quantum Gravity: Early Universe dynamic

Author: G. Montani.

Abstract: A brief review concerning the problem of time in Quantum Gravity is provided in order to outline possible links with the canonical framework of quantization.
The implications of restricting the covariance principle within a Gaussian gauge are developed both on a classical and a quantum level. Hence, we investigate the cosmological issues of the obtained Schrodinger Quantum Gravity with respect to the asymptotically early dynamics of a generic Universe. A dualism between time and the reference frame fixing is then inferred.

_C. Perini

Title: Comparing Loop Quantum Gravity with the linearized theory

Authors: E. Magliaro, C. Perini

Abstract: In the first part of the talk E.M. will illustrate the conceptual scenario of the general boundary formulation for field theories and will present a brief description of the calculus of graviton propagator performed by E. Bianchi, L. Modesto, C. Rovelli e S. Speziale in the context of LQG.
In the second part C.P. will analyze the possibility of comparing this result with the graviton propagator in perturbative quantum gravity. For this purpose he will present the result of a recent work that demonstrates the compatibility of harmonic and radial gauge; it allows to simultaneously impose both gauges and to obtain an expression for the propagator comparable with the one provided by LQG.

_M. Pizzi

Title: Electric force lines of the double Reissner-Nordstrom solution

Authors: A. Paolino, M. Pizzi.

Abstract: We show the behavior of the electric field of a new exact solution of the Einstein-Maxwell equation, recently found by Alekseev and Belinski, which describes two Reissner-Nordstrom (RN) sources in reciprocal equilibrium. Different configurations of physical relevance are investigated. In particular we considered the limit case of a charged test particle near a Schwarzschild black hole, comparing and confirming also the correctness of the Hanni-Ruffini plots.

_M. Rotondo

Title: On the nuclear matter in bulk: from nuclei to neutron cores

Authors: M. Rotondo, B.Patricelli, R.Ruffini, S.S. Xue

Abstract: Using the relativistic Thomas-Fermi equation we present an approach to analyze the electrodynamics of nuclear matter in bulk. We generalize to the case of A=1057 nucleons of mass mn  an approach well tested in heavy nuclei with A=106. Particular attention is given to implement the condition of charge neutrality globally on the entire configuration versus the one usually adopted on a microscopic scale. Incidentally, we give a method to calculate, from first principles, the mass relation which runs from nuclei to neutron cores. It is shown that an overcritical electric field close to the critical value of vacuum polarization  near the core surface develops. Finally, we see that the equilibrium configurations which obey the global charge neutrality are energetically favorable with respect to the ones which obey  the local charge neutrality. These results can have important consequences on the understanding of physics process in neutron stars structure as well as on the initial conditions leading to the process of gravitational collapse to a black hole.

_C. Sigismondi

Title: Meteotsunami detection in Adriatic and Tyrrenian sea

Author: Costantino Sigismondi

Abstract: Local atmospheric pressure variations of 1 hPa produce sea level changes of 1 cm which start to propagate like shallow water waves. Meteotsunami are such long waves originated by atmosferic perturbations. Such waves in semi-enclosed seas or lakes become oscillating seiches with frequency dependent on basin's geometry. Summer seiches activity in central Adriatic and Tyrrenian sea is larger than tidal variation of sea surface on timescales shorter than one hour. We adapetd ultrasonic detectors with acquisition rate of 100 data per minute to monitor the elevation of sea surface. Our datasets lasting up to three hours recorded in July-September 2007 are analyzed in order to understand the dynamics of those long waves.

_G. Vereshchagin

Title: Semi-classical Loop Quantum Cosmology

Author: G.V. Vereshchagin

Abstract: Cosmological solutions with scalar field in Loop Quantum Cosmology with a number of effective potentials will be discussed. We will show how quantum modifications in the Friedmann equation prevent occurence of cosmic singularities. Qualitative analysis with phase portrait technique will be presented. Such features of solutions as inflation as well as cyclic behavior will be considered.

Title: Thermalization of the pair plasma

Authors: A.G. Aksenov, R. Ruffini, G.V. Vereshchagin

Abstract: Starting from a nonequilibrium configuration we analyse the essential role of the direct and the inverse binary and triple interactions in reaching an asymptotic thermal equilibrium in homogeneous isotropic electron-positron-photon plasma. We focus on the energies in the range 0.1-10 MeV. We integrate numerically integro-partial differential relativistic Boltzmanns equation with the exact QED collisional integrals taking into account all binary and triple interactions in the plasma. We show that first, when detailed balance is reached for all binary interactions on a timescale t_{k}<~10^{-14}sec, photons electron-positron pairs establish kinetic equilibrium. Successively, when triple interactions fulfill the detailed balance on a timescale t_{eq}<~10^{-12}sec, the plasma reaches thermal equilibrium. It is shown that neglecting the inverse triple interactions prevents reaching thermal equilibrium. Our results obtained in the theoretical physics domain find also applications in astrophysics and cosmology.

_S. S. Xue

Title: electron-positron productions in inhomogeneous electric fields.

Authors: R. Ruffini, S. S. Xue

Abstract: we calculate the semi-classical WKB-rate of electron-positron productions in inhomogeneous electric fields, provided energy-level crossings occur between the negative and positive energy-spectra.

_R. Zalaletdinov

Title: Macroscopic Gravity and Averaging Problem in Cosmology

author: R. Zalaletdinov

Abstract: The Averaging problem in general relativity and cosmology is discussed. The approach of macroscopic gravity to resolve the problem is presented. The averaged Einstein equations of macroscopic gravity are modified on cosmological scales by the gravitational correlation tensor terms as compared with the Einstein equations of general relativity. This correlation tensor satisfies an additional set of structure and field equations. Exact cosmological solutions to the equations of macroscopic gravity for spatially homogeneous and isotropic macroscopic space-times are presented. In particular, it has been found that for a flat geometry the gravitational correlation tensor terms in the averaged Einstein equations have the form of a spatial curvature term which can be either negative or positive. Thus macroscopic gravity provides a cosmological model for a flat spatially homogeneous and isotropic Universe which obeys the dynamical law for either open or closed Universe geometry. Other exact solutions are presented and their physical and cosmological interpretation is discussed.

_F. Zonca

Title: The Physics of Burning Plasmas in Toroidal Magnetic Field Devices

Author: F. Zonca

Abstract: Some of the crucial physics aspects of burning plasmas magnetically confined in toroidal systems are presented from the viewpoint of nonlinear dynamics.
Most of the discussions specifically refer to tokamaks, but they can be readily extended to other toroidal confinement devices. Particular emphasis is devoted to fluctuation induced transport processes of mega electron volts energetic ions and charged fusion products as well as to energy and particle transports of the thermal plasma. Long time scale behaviours due to the interplay of fast ion induced collective effects and plasma turbulence are addressed in the framework of burning plasmas as complex self-organized systems. The crucial roles of mutual positive feedbacks between theory, numerical simulation and experiment are shown to be the necessary premise for reliable extrapolations from present day laboratory to burning plasmas. Examples of the broader applications of fundamental problems to other fields of plasma physics and beyond are also given.

_S. Zonetti

Title: The parametrizing fluids in canonical Quantum Gravity

Authors: S. Zonetti, G. Montani

Abstract: we present the parametrizing fluids as possible solution for the problem of time in canonical quantum gravity: we review and apply the Kuchar-Brown mechanism on two general classes of fluids, searching for a physical hamiltonian that generates the time evolution.