Warning: these informations are still tentative.
Authors: R. Ruffini, M.G. Bernardini, C.L. Bianco, L. Caito, P. Chardonnet, M.G. Dainotti, R. Guida, S.-S. Xue.
Title: On selected classes of GRBs
Abstract: The three paradigms for the GRB interpretation [ApJL 555 (2001) L107, L113, L117] are here revisited in light of the recent theoretical developments and observational supports. In particular, the sources GRB 970228 and GRB 060614 are considered and shown to have a fundamental role in understanding a new family of GRBs. Similarly, the source GRB 061007 is examined and, again, shown to be representative of a different GRB class. Finally, the sources associated with supernova are examined, presenting a third different class. The crucial role of the P-GRB in understanding short and long GRBs is discussed. Details will be given in the accompanying contributions. Authors: M.G. Bernardini, C.L. Bianco, L. Caito, P. Chardonnet, M.G. Dainotti, R. Guida, R. Ruffini, S.-S. Xue. Title: A new interpretation of GRB 970228 Abstract: GRB 970228 has been analyzed within our theoretical framework as a prototype for a new class of GRBs, characterized in the current literature by "hybrid" properties between short and long GRBs. Detailed theoretical computation of the GRB 970228 light curves in selected energy bands as well as of the instantaneous and time-integrated spectra are presented and compared with observational BeppoSAX data. Considerations on this new GRB class are also presented.
Authors: L. Caito, M.G. Bernardini, C.L. Bianco, P. Chardonnet, M.G. Dainotti, R. Guida, R. Ruffini, S.-S. Xue.
Title: On GRB 060614
Abstract: GRB 060614 is examined within our theoretical framework. This burst displays unusually an hard-multipeaked emission followed by an extended soft one. The most interesting peculiarity of this source is that, although it lasts about one hundred seconds and its redshift is very low (0.125), there is no evidence of an associated supernova explosion. This source belongs to a distinct alternative GRB class, which has its prototype in GRB 970228.
Authors: R. Guida, M.G. Bernardini, C.L. Bianco, L. Caito, P. Chardonnet, M.G. Dainotti, R. Ruffini, S.-S. Xue.
Title: On GRB 061007
Abstract: Taking the gamma and X ray data from SWIFT, GRB 061007 is examined within our theoretical model. The behaviour of the light curve is unusual for a SWIFT burst in the sense that it shows an remarkably simple power-law decay from gamma rays to optical-wavelengths. Its isotropic equivalent radiated energy is one of the highest ever measured (greater than 10^54 erg) and its peak nuFnu energy is well determined. It therefore provides a useful test of current spectral energy correlations with all the details of its structured light curves. This source appears to belong to the same GRB class of GRB 991216.
Authors: C.L. Bianco, M.G. Bernardini, L. Caito, P. Chardonnet, M.G. Dainotti, R. Guida, R. Ruffini, S.-S. Xue.
Title: The role of P-GRB in understanding short and long GRBs.
Abstract: The theoretical understanding of the P-GRB needs the comprehension of the source as well as the detailed knowledge of the optically thick phase of the expansion and the reaching of transparency. Some recent developments of our theoretical framework on this subject are discussed.
Authors: M.G. Dainotti, M.G. Bernardini, C.L. Bianco, P. Chardonnet, R. Guida, R. Ruffini, S.-S. Xue.
Title: GRB 060218: another example of GRB-Supernova connection.
We study the Gamma-Ray Burst (GRB) 060218 related to SN 2006aj. This source appears to be a very soft burst and has been interpreted as an X-Ray Flash (XRF). We successfully fit the entire set of X- and gamma-ray observations by Swift of GRB 060218 in the 0.3-150 keV energy band during the entire time of observations within a unified theoretical model. We make as well definite predictions about the spectral distribution in the early part of the light curve. By our fit we show that there are no basic differences between XRFs and more general GRBs.
Authors: Maria Grazia Bernardini, Carlo Luciano Bianco, Letizia Caito, Maria Giovanna Dainotti, Roberto Guida, Remo Ruffini.
Title: GRB970228: a prototype for a new GRB class.
Abstract: GRB970228 has been analyzed within our theoretical framework as a prototype for a new class of GRBs, characterized by "hybrid" properties between short and long GRBs. Detailed theoretical computation of the GRB970228 light curves in selected energy bands as well as of the instantaneous and time-integrated spectra are presented and compared with observational BeppoSAX data.
Authors: Carlo Luciano Bianco, Maria Grazia Bernardini, Letizia Caito, Maria Giovanna Dainotti, Roberto Guida, Remo Ruffini.
Title: Theoretical interpretation of GRB060614
Abstract: GRB060614 is examined within our theoretical framework. This burst displays unusually an hard-multipeaked emission followed by an extended soft one. The most interesting peculiarity of this source is that, although it lasts about one hundred seconds and its redshift is very low (0.125), there is no evidence of an associated supernova explosion.
Authors: Donato Bini, Andrea Geralico
Title: Connecting vectors and relativistic strains
Abstract: The definition of relative accelerations and strains among a set of comoving particles is studied in connection with the geometric properties of the frame adapted to a "fiducial observer". A relativistically complete and correct definition of strains is given taking into account the transport law of the chosen spatial triad along the observer's congruence. The celebrated idea of Szekeres' compass of inertia is then generalized, contributing also to the theory of relativistic gravity gradiometer. The observer-dependent form of our analysis might be very useful when thinking about general relativistic tests on space stations orbiting compact objects like black holes and also in other interesting gravitational situations.
Authors: Letizia Caito, Maria Grazia Bernardini, Carlo Luciano Bianco, Maria Giovanna Dainotti, Roberto Guida, Remo Ruffini.
Title: Theoretical interpretation of GRB011121
Abstract: The most recent developments in Gamma-Ray Burst's (GRB) observations have imposed as a characteristic of strong interest the presence of some flares in the afterglow of many GRB sources. The explanation of these bumps in the light curves is a very important issue to resolve for the understanding of the GRB phenomenon. In this work, GRB011121 is analyzed as a prototipe to understand the flares recently observed by Swift. Detailed theoretical computations of the GRB011121 light curves in selected energy bands are presented and compared with observational BeppoSAX data.
Authors: Christian Cherubini, Simonetta Filippi
Title: Scattering problems on rotating acoustic black holes
Abstract: Analog curved spacetimes emerging from non relativistic consensed matter systems can be very useful to understand General Relativistic effects. Scattering problems on rotating acoustic black holes in particular can be studied in the time domain by using numerical methods only. In order to obtain high quality results in simulations, tools developed by numerical relativists in the case of rotating Kerr black holes must be adopted, i.e. constrained evolution schemes for strongly symmetric and non symmetric hyperbolic systems of PDEs and excision techniques in horizon penetrating coordinates. In this talk such a program is presented and analogies between astrophysical and acoustic black holes are discussed in relation with Press and Teukolsky's relativistic "black hole bomb."
Authors: Francesco Cianfrani, Giovanni Montani
Title: Classical and Quantum features of the spin-curvature coupling.
Abstract: We analyze the behavior of a spinning particle in gravity, both from a quantum and a classical perspective point of view. We infer that, since the interaction between the space-time curvature and a spinning test particle is expected, then the main features of such an interaction can get light on which degrees of freedom have physical meaning in a quantum gravity theory with fermions. Finally, the dimensional reduction of Papapetrou equations is performed in a 5-dimensional Kaluza-Klein background and Dixon-Souriau results for the motion of a charged spinning body are obtained.
Authors: Maria Giovanna Dainotti, Maria Grazia Bernardini, Carlo Luciano Bianco, Letizia Caito, Roberto Guida, Remo Ruffini.
Title: GRB060218: another example of GRB-Supernova connection.
Abstract: We study the Gamma-Ray Burst (GRB) 060218 related to SN 2006aj. This source appears to be a very soft burst, therefore interpreted as an X-Ray Flash (XRF). We successfully fit the entire set of X- and gamma-ray observations by Swift of GRB 060218 in the 0.3-150 keV energy band during the entire time of observations within a unified theoretical model. We make as well definite predictions about the spectral distribution in the early part of the light curve. By our fit we show that there are no basic differences between XRFs and more general GRBs.
Authors: Simonetta Filippi, Christian Cherubini, Remo Ruffini, Alonso Sepulveda
Title: Generalized axisymmetric models of self-gravitating systems
Abstract: Non-homogeneous axisymmetric models of self-gravitating systems are discussed by using functional methods and integrability conditions are established in the case of barotropic and baroclinic configurations. For various velocity profiles, in the case of polytropic index n=1, analytic approaches are tempted by using the matching techinque developed by Williams in 1987 in order to find the density profile and in particular the configuration's surface.
Authors: Andrea Geralico, Donato Bini, Remo Ruffini
Title: Perturbations of a Reissner-Nordstrom black hole by a charged massive particle at rest
Abstract: A new perturbative solution describing a two-body system consisting of a Reissner-Nordstrom 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.
Authors: Roberto Guida, Maria Grazia Bernardini, Carlo Luciano Bianco, Letizia Caito, Maria Giovanna Dainotti, Remo Ruffini
Title: The Amati relation and the atypical case of GRB980425
Abstract: The existence of the phenomenological Amati relation is discussed within our theoretical GRB model. In this framework we perform a reanalysis of GRB980425, the only clear long GRB which does not follow such relation. Possible reasons for its peculiar behavior are discussed.
Authors: Orchidea Maria Lecian, Giovanni Montani
Title: Lorentz gauge theory and its phenomenological implications
Abstract: A gauge theory of the Lorentz group, based on the different behaviour of spinors and vectors under local space-time transformations, is formulated. The role of the torsion field within this gauge scheme is discussed and Lorentz connections are identified with suitable bein projections of the contortion field. Our approach predicts a propagating torsion field having the density spin current as a source, and, in this sense, provides an extension of the U^4 theory. An application of this theory to an accelerated beam of electrons is proposed; therefore, an upper limit to the Lorentz interaction coupling constant is discussed.
Authors: Michael Rotondo, Vladimir Popov, Remo Ruffini, She-Sheng Xue
Title: Electrodynamics for neutron stars: generalized analytical solutions
Abstract: The relativistic Thomas-Fermi equation and energetic equation of beta equilibrium are used to describe degenerate neutrons, protons and electrons in neutron stars. The analytical approach is adopted to found equilibrium configurations which obey the global neutrality. Several generalized exact solutions are presented and discussed.
Authors: Remo Ruffini, Maria Grazia Bernardini, Carlo Luciano Bianco, Donato Bini, Letizia Caito, Pascal Chardonnet, Maria Giovanna Dainotti, Federico Fraschetti, Andrea Geralico, Roberto Guida, Michael Rotondo, Gregory V. Vereshchagin, She-Sheng Xue.
Title: The physics of GRBs
Abstract: The fundamental role of recent astrophysical observations pertaining to GRBs are shown to promote a revival of fundamental issues in GRBs, in black hole physics and in relativistic quantum field theory. The possibility to observe for the first time the process of vacuum polarization at the energy scale of 10^54 ergs is presented. The profound consequences of the results on the physics of neutron stars and on black hole electrodynamics are presented and discussed. Some new perspectives in relativistic quantum field theory are as well outlined.
Authors: Alonso Sepulveda, Christian Cherubini, Simonetta Filippi, Remo Ruffini, Jorge Iván Zuluaga Callejas
Title: Non-homogeneous axisymmetric models of self-gravitating systems: the numerical matching.
Abstract: Non homogeneous axisymmetric models of self-gravitating systems are discussed by using functional methods and numerical techinques. More in detail, in a reference frame, rotating with constant angular velocity Omega, a self-gravitating incompressible fluid, in steady state is considered. In particular the internal velocity field has flow lines normal to the global angular velocity. Deriving a generalized Lane-Emden equation and using a procedure inspired by the method of Eriguchi-Muller, for selected velocity profiles, a sequence of equilibrium configurations is found and discussed.
Authors: Gregory V. Vereshchagin, Remo Ruffini, She-Sheng Xue
Title: On vacuum polarization and plasma oscillations
Abstract: Vacuum polarization in a strong electric field results in electron-positron pair creation. We study collective effects in the pair plasma emerged in this way, including vacuum polarization itself, back-reaction of the plasma on initial electric field and plasma oscillations. With this goal we consider energy conservation and electromagnetic field equations, comparing these to the traditional Vlasov-Boltzmann treatment. We conclude that under certain conditions plasma oscillations may occur in a weak electric field. We present single equation describing these oscillations in the weak field limit. Time and length scales of oscillations are discussed.
Author: She-Sheng Xue, Vladimir Popov, Michael Rotondo, Remo Ruffini
Title: Energetically favorable electrodynamical configuration for neutron stars
Abstract: We use the relativistic Thomas Fermi equation and energetic equation of beta equilibrium to describe degenerate neutrons, protons and electrons in neutron stars. An analytical approach are adopted to analyze these equations, implemented with the global neutrality: total proton and electron numbers are the same. We find a unique configuration of protons and electrons distributions which has an critical electric field at the surface of neutron stars. It is shown that such an electrodynamic configuration is (i) energetically stable against the Coulomb repulsion; and (ii) energetically favorable, against the configuration which obeys the local neutrality: proton and electron number-densities are the same in neutron stars.
Author: Donato Bini
Title: Relativistic strains and special congruences in some familiar spacetimes.
Abstract: The relativistic strains experienced by a bunch of test particles when moving (arbitrarily) in certain familiar spacetimes (e.g. stationary and axisymmetric spacetimes) are investigated in view of possible applications to the study of jet-like structures formation.