Speaker: Alexei Aksenov
Title: Kinetics of GRB 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 electronpositronphoton plasma. We focus on the energies in the range 0.110 MeV. We integrate numerically integropartial 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}≲10⁻¹⁴sec, photons and electronpositron pairs establish kinetic equilibrium. Successively, when triple interactions fulfill the detailed balance on a timescale t_{eq}≲10⁻¹²sec, 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.
Speaker: Lorenzo Amati
Title: Spectralenergy correlations in GRB: recent updates and implications
Author: L. Amati
Abstract: The correlation between the photon energy at which the redshift corrected nuFnu spectrum peaks (hence called "peak energy", Ep,i) and the isotropic equivalent radiated energy (Eiso), is one of the most intriguing and debated observational evidences in Gamma Ray Bursts (GRB) astrophysics. I present the updated Ep,i  Eiso correlation and discuss its main implications for the physics and geometry of the GRB emission, with particular emphasis on the properties of Swift GRBs and the location in the Ep,iEiso plane of subenergetic long GRBs, GRB/SN events, short GRBs and the recently discovered subclass of long GRBs without association with a hypernova.
Speakers: Marco Valerio Battisti
Title: Quantum features of the FRW singularity from a generalized
uncertainty principle point of view
Authors: M.V.Battisti and G.Montani
Abstract: The quantum dynamics of the FriedmannRobertsonWalker Universe with a
massless scalar field is analyzed in the Generalized Uncertainty
Principle framework. The system is quantized using an extended
formulation of the Heisenberg algebra and the scalar field is regarded
as a relational clock for the dynamics. The behavior of the Universe
near the classical singularity is analyzed via the motion of suitable
wave packets. Such a dynamics appears to be nonsingular, but no
evidence for a quantum bounce arises.
Speakers: Volodia Belinski and Marco Pizzi
Title: The fields of a naked singularity and black hole in mutual equilibrium
Authors: G. Alekseev, V. Belinski, A. Paolino, M. Pizzi
Abstract: An asymptotically flat static solution of EinsteinMaxwell equations which describes the field of two Reissner  Nordstrom sources in equilibrium is presented. It was shown that the equilibrium is possible only when one of the sources is a black hole and another one is a naked singularity. The diagrams of the force lines of electrical field is constructed.
Speaker: Riccardo Benini
Title: Quasiclassical and Quantum properties of the Mixmaster model
Authors: R. Benini, G. Montani
Abstract: In this talk we discuss several properties of the Mixmaster model.
The ADM Hamiltonian framework is here adopted, and the dynamics reduced to the physical degrees of freedom.
On the quasiclassical level, the HamiltonJacobi equation and the mechanicalstatistical point of view are discussed in some
detail; the operatorordering to be used on the quantum level is also fixed.
A full description of the Schroedinger dynamics is then provided, and the eigenfunctions,
the energy levels and the properties of the spectrum are analized both analytically and numerically.
Speaker: Maria Grazia Bernardini
Title: GRB970228 and a class of GRBs with an initial spikelike emission.
Authors: M. G. Bernardini, C. L. Bianco, L. Caito, M. G. Dainotti, R. Guida, R. Ruffini
Abstract: On the basis of the recent understanding of the Swift sources GRB050315 and GRB060218, we return to GRB970228, the first GammaRay Burst (GRB) with detected afterglow. It appears to be the prototype for a recently proposed new class of GRBs with "an occasional softer extended emission lasting tenths of seconds after an initial spikelike emission''. Detailed theoretical computation of the GRB970228 light curves in selected energy bands both for the prompt and the late afterglow emission are presented and compared with observational BeppoSAX data. From our analysis we conclude that, far from forming a new class of sources straddling both short and long bursts, GRB970228 and likely the ones of the above mentioned new class of GRBs are "canonical" GRBs have only one peculiarity: they exploded in a galactic environment, possibly the halo, with a very low value of ISM density.
Speaker: Carlo Luciano Bianco
Title: The "canonical GRB" scenario
Authors: C.L. Bianco, M.G. Bernardini, L. Caito, P. Chardonnet, M.G. Dainotti, R. Guida, R. Ruffini, S.S. Xue.
Abstract: In our model we define a "canonical GRB" light curve with two sharply different components: the ProperGRB (PGRB), emitted when the optically thick fireshell of electronpositron plasma originating the phenomenon reaches transparency, and the afterglow, emitted due to the collision between the remaining optically thin fireshell and the CircumBurst Medium (CBM). Our "canonical GRB" scenario, originating from the gravitational collapse to a black hole, will be presented and discussed.
Speaker: Donato Bini
Title: Strains and axial outflows in the field of a rotating black hole
Author: D. Bini
Abstract: We study the behaviour of an initially spherical bunch of accelerated particles emitted along trajectories parallel to the symmetry axis of a rotating black hole.
We find that, under suitable conditions, curvature and inertial strains compete to model the shape of axial outflows of matter contributing to generate jetlike structures.
This is a purely kinematical effect which does not account by itself for physical processes underlying the formation of jets.
Speaker: Letizia Caito
Title: GRB060614: a progress report
Authors: L. Caito, M.G. Bernardini, C.L. Bianco, M.G.
Dainotti, R. Guida, R. Ruffini
Abstract: GRB 060614 is examined within our theoretical
framework. This burst displays unusually an hardmultipeaked
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.
Speaker: Salvatore Capozziello
Title: Dark Energy and Dark Matter or Extended Gravity?
Author: S. Capozziello
Abstract: Higher order theories of gravity have recently attracted a lot of interest as alternative candidates to explain the observed cosmic acceleration, the flatness of the rotation curves of spiral galaxies and other relevant astrophysical phenomena. Very likely, what we call “dark matter” and “dark energy” are nothing else but signals of the breakdown of General Relativity at large scales. Furthermore, PPNparameters deduced from Solar System experiments do not exclude, a priori, the possibility that such theories could give small observable effects also at these scales. We review these results giving the basic ingredients of such an approach.
Speaker: Nakia Carlevaro
Title: Study of the Quasiisotropic Solution near the Cosmological
Singularity in Presence of BulkViscosity
Authors: N. Carlevaro, G. Montani
Abstract: This talk is fucused on the analysis of the dynamical
behavior of a quasiisotropic Universe in the presence of a
cosmological fluid endowed with bulk viscosity. The viscosity
coefficient is expressed as a powerlaw of the fluid energy density:
$\zeta=\zeta_0 \epsilon^{s}$. Then the exponent s is fixed equal to 1/2
as the only case in which viscosity plays a significant role in the
singularity physics but it does not dominate the Universe dynamics.
Following the line of the work by E.M. Lifshitz and I.M. Khalatnikov,
the Einstein and hydrodynamic equations are analyzed up to first and
second order in time. As main result is shown that the quasiisotropic
solution exists only for particular values of the bulk viscosity
coefficient $\zeta_0$. When the dissipative effects become too
relevant, the solution of the LK model can not be addressed. In fact,
when $\zeta_0$ approaches a threshold value, the approximation scheme
fails and the model becomes non selfconsistent. By requiring that the
viscosity parameter be under its critical value the behavior of the
density contrast is analyzed in presence of bulk viscosity: the
evolution, toward the singularity, is damped until remaining constant
if $\zeta_0$ assumes its critical value.
Speaker: Sabrina Casanova
Title: The galactic plane survey performed by the Milagro detector
Authors: S. Casanova
Abstract: TBA
Speaker: Valery Chechetkin
Title: Mechanism of explosion of supernovae
Author: V. Chechetkin
Abstract: TBA
Speaker: Christian Cherubini
Title: On the Energetics of the Dyadotorus
Authors: Christian Cherubini, Simonetta Filippi
Abstract: A quasilocal mechanical energy is defined and discussed in the case of a KerrNewman black hole. Possible astrophysical implications for QED effects around charged and rotating black holes are discussed.
Speaker: Francesco Cianfrani
Title: Boost symmetry in the Quantum Gravity sector
Author: F. Cianfrani
Abstract: We perform a canonical quantization of gravity in a secondorder formulation, taking as configuration variables those describing a 4bein, not adapted to the spacetime 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.
Speaker: Christian Corda
Title: Tuning the stochastic background of gravitational waves with theory and observations
Authors: C. Corda, S. Capozziello and M. F. De Laurentis
Abstract: The stochastic background of gravitational waves (SBGWs) is analyzed wih the auxilium of the WMAP data. We emphasize that, in general, in the literature about the SBGWs, old COBE data are used. After this, we face the problem of how the SBGWs and f(R) gravity theories can be related, showing, vice versa, that a revealed SBGWs could be a powerly probe for a given theory of gravity. In this way, it will also be shown that the conformal treatment of SBGWs can be used to parametrize in a natural way f(R) theories. Because F(R) theories admit, in general, a third scalar polarization of GWs, at the end of the talk the crosscorrelation between the Virgo interferometer and the Minigrail resonant sphere for the potential detection of a scalar SBGWs in the massless case is shown.
Speaker: Stefano Covino
Title: Direct Measurement of the Initial Lorentz Gamma Factor for GammaRay Burst Afterglows
Author: S. Covino
Abstract: Gammaray burst are thought to be produced by highly relativistic outflows. Although upper and lower limits for the outflow initial Lorentz factor are available, observational efforts to derive a direct determination of this fundamental parameter have so far failed or provided ambiguous results. As a matter of fact, the shape of the earlytime afterglow light curve is strongly sensitive on the Gamma Lorentz Factor which determines the time of the afterglow peak, i.e. when the outflow and the shocked circumburst material share a comparable amount of energy. We now comment earlytime observations of the nearinfrared afterglows of GRB 060418 and GRB 060607A performed by the REM robotic telescope. For both events, the afterglow peak was singled out and allowed us to determine the initial fireball Lorentz, Γ ∼ 400.
Speaker: Maria Giovanna Dainotti
Title: GRB060218 and GRBs associated with Supernovae Ib/c
Authors: M.G. Dainotti, M.G. Bernardini, C.L. Bianco, L.
Caito, R. Guida, R. Ruffini
Abstract: The Swift satellite has given continuous data in the range
0.3150 keV from 0 s to 106 s for GRB060218 associated with
SN 2006aj. These data offer the unprecedented opportunity to
probe theoretical models for GammaRay Bursts (GRBs)
connected with Supernovae (SNe). We fit the entire set of
data of this extremely long duration GRB (T_{90} ~ 2100 s),
including the prompt emission. The baryon loading B =
10^{2} coincides with the upper limit for the dynamical
stability of the electronpositronbaryon plasma generating
the GRB. Such an extreme value is here encountered for the
first time. The effective CircumBurst Medium (CBM) density
shows a radial dependence n_{cbm} \propto r^{\alpha}, with
\alpha \simeq 1, and ranges between 10^{6} < n_{cbm} < 1
particle/cm3. Such a low effective CBM density, essential
to explain the high T_{90} value, is interpreted as due to a
fragmentation in the accelerated baryonic shell. This
fragmentation, consistent with the instabilities implied by
a baryon loading B = 10^{2}, leads to an actual CBM density
n_{cbm}^{act} \simeq 1.0 particle/cm3. Analogies with the
fragmented density of the Novae are outlined. The smallest
possible black hole, formed by the gravitational collapse of
a neutron star in a binary system, appears to explain the
especially low energetics of these GRBs associated with SNe.
Speaker: Massimo Della Valle
Title: Supernovae and GRBs: when stars fade in the shade
Author: M. Della Valle
Abstract: In this talk I'll shortly review (with an observational perspective) the
"status" of the SupernovaGRB connection.
Speaker: Ruben Farinelli
Title: Transition layers around compact objects (black holes and neutron stars):
Evolution of their hydrodynamical structure and size
as a function of the mass accretion rate
Author: Ruben Farinelli
Abstract: Accretion from a Keplerian disk into a subKeplerian rotating central
object, which can be either a black hole (BH) or a neutron star (NS),
should produce a transition layer (TL) region, whose radial extension
strongly anticorrelates with an effective Reynolds (Re) number of the
flow, related to the mass accretion rate.
The TL main characteristics are determined by
a set of physical quantities, such as Renumber, the mass accretion
rate, the electron temperature of the infalling flow, the
strength of the magnetic field and the viscosity. We present
numerical results on the structure of the TL obtained from a full
magnetohydrodinamical treatment of the problem. We show that at low
mass accretion rates (dm/dt << 1) the TL radial profile of the velocity
field is characterized by a freefalllike behaviour in
the innermost part of the region. On the other hand, as dm/dt
increases, the qualitative behaviour of the radial velocity field is
completely different for the NS and BH cases.
The main reason for this difference is not, as it was previously
expected, due to the direct radiation pressure coming from the NS (which is
absent in BH) but it is due to the fact that the firm surface of the NS
acts as a mirror, reflecting the radiation produced by release of
gravitokinetic energy in the TL. As a consequence of this fundamental
difference, in systems hosting a NS the TL layer heightscale must increase
as dm/dt increases, to allow matter to reach the NS firm surface. On the
contrary, the radiation pressure gradient finally stops the infalling
material. This effect is not present in the case of BH, where matter flows
within the event horizon.
Speaker: Filippo Frontera
Title: The Cosmic Xray background at the peak of its emission: new results and implications
Author: F. Frontera
Abstract: I will report on an accurate measurement of the CXB in the 1550 keV range
performed with the PDS instrument aboard the BeppoSAX satellite. Our
measurement is the best available after that obtained over 25 years ago with the
first High Energy Astronomical Observatory satellite mission (HEAO1), that provided
a CXB intensity well below the extrapolation of several lower energy measurements
recently performed with focusing telescopes. For this reason it is questioned.
I will discuss our results and its astrophysical implications.
Speaker: Walter Greiner
Title: Supercritical fields and
short living giant atoms
Author: W. Greiner
Abstract: I outline the basics and also discuss
the recent ideas of testing supercriticality in collisions of the type
U+Cm where we expect large sticking times of the giant atoms.
Speaker: Dafne Guetta
Title: Selection effects in GRB redshift determination
Author: D. Guetta
Abstract: TBA
Speaker: Roberto Guida
Title: GRB050315 and the Amati relation
Authors: R. Guida, M.G. Bernardini, C.L. Bianco, L. Caito,
M.G. Dainotti, R. Ruffini
Abstract: The existence of the phenomenological Amati relation is
discussed within our theoretical GRB model. In this
framework we perform a reanalysis of GRB050315, a canonical
GRB which follow this relation. Possible reasons for some of
the outliers of this relation are given.
Speaker: Vahe Gurzadyan
Title: Dark energy, vacuum fluctuations vs observational data
Author: Vahe Gurzadyan
Abstract: The correlations in the cosmic microwave background radiation pixelized temeperature maps will be discussed with the determination of the excursion sets and their properties.
Speaker: Hagen Kleinert
Title: The Many Uses of Mutivalued Fields in Theoretical Physics
Author: H. Kleinert
Abstract: I show that multivalued fields, i.e., which do not possess commuting derivatives,
play an essential role in understanding gauge theories of many physical systems
such as superfluids, superconductivity, quark confinement.
They also provide us with a method to predict the physical laws
in curved space from those in flat space.
Speaker: Orchidea Maria Lecian
Title: Scalartensor analysis of an exponential Lagrangian for the
Gravitational Field
Authors: Orchidea Maria Lecian, Giovanni Montani
Abstract: Within the scheme of modified gravity, an exponential Lagrangian density will be considered, and the corresponding scalartensor description will be addressed for both positive and negative values of the cosmological constant.
For negative values of the cosmological term, the potential of the scalar field exhibits a minimum, around which scalarfield equations can be linearized. The study of the deSitter regime shows that a comparison with the modifiedgravity description is possible in an offshell region, i.e., in a region where the classical equivalence between the two formulations is not fulfilled. Furthermore, despite the negative cosmological constant, an accelerating deSitter phase is predicted in the region where the series expansion of the exponential term does not hold.
For positive values of the cosmological constant, the quantum regime is analyzed within the framework of Loop Quantum Cosmology.
Speaker: Luca Lusanna
Title: The York Map and the Role of NonInertial Frames in the Geometrical View
of the
Gravitational Field
Author: L. Lusanna
Abstract: The role of noninertial frames in a class of models of general
relativity is clarified by means of Dirac's theory of constraints.
The identification of a York canonical basis allows to give the
interpretation of the gauge variables as generalized inertial
effects and to identify the Dirac observables of the gravitational
field with generalized tidal effects. York time is the gauge
variable controlling the clock synchronization convention.
Differently from special relativity, the instantaneous 3spaces are
dynamically determined and at least part of dark matter could have
inertial origin.
Speaker: Luis Juracy Rangel Lemos
Title: TBA
Authors: Luis Juracy Rangel Lemos, Sabrina Casanova
Abstract: High energy protons predicted in the fireshell scenario for Gamma Ray
Bursts (GRBs) scatter off the interstellar medium close to the GRBs. The
pions produced in the inelastic pp collision will further decay in two
high energy gamma rays. A distribution for the resulting pions and gamma
rays are given. The pion distribution predicted by the Fermi model is
here compared with the experimental measurements and with recent models
for the inelastic pp interactions.
Speaker: Costantino Sigismondi
Title: Solar radius in 2006
Author: C. Sigismondi
Abstract: A program of recovering solar diameter from eclipse is tested with 2006
data
(Egypttotal eclipse and French Guyanaannular eclipse).
Errors in UTC timing and lunar and solar ephemerides are discussed in
order to detect diameter's fluctuations and oblateness parameter.
Title: Perturbations to Astronomical Tides in Pescara Seaport
Author: C. Sigismondi, G. Bernardini
Abstract: Fast Fourier Transform of sea levels measured each second with
an ultrasonic distance sensor in Pescara Seaport show high frequency
(less than 1 hour) long waves. A comparison with nearby seaports is
made. Those seiches, which are the fastest gravity waves, with
amplitudes occasionally up to 40 cm, appear to be typical signatures for
central Adriatic sea level.
Speaker: Lev Titarchuk
Title: On the Nature of Xray Power and Energy Spectra from Black Holes and Neutron Stars. A New Method of Black Hole Mass Determination
Author: Lev Titarchuk
Abstract: We present a new paradigm to interpret the observed Xray spectral/temporal characteristics of accreting galactic black hole (BH) and neutron star (NS)systems. This paradigm is based on a generic models of spectral and power spectra formations which we have developed over the last decade.
The paradigm provides a physical picture for the primary region of Comptonization close to the central object. It relates the dynamical evolution of this region to the spectral state of the source and identifies the mechanisms responsible for many of the temporal and spectra features observed. This model has successfully explained the observed correlations between low QPO frequency and photon index reported in a number of Galactic BH sources. Furthermore, the model shows how the mass of the central object can be obtained from these correlations and provides a new way to use their high frequency properties to distinguish between NSs and BHs.
To date the development of the paradigm and its application to the study of BHs and NSs is documented in more than 60 papers published in leading refereed journals.
The overall aim of this study is to arrive at a synthesis of the information contained in timing and spectral data that explains and forms a comprehensive understanding of compact accreting objects and helps to guide the planning of future observations and missions.
Speaker: Gregory Vereshchagin
Title: Pair creation and plasma oscillations
Authors: R. Ruffini, G.V. Vereshchagin, S.S. Xue
Abstract:
We evidence the existence of plasma oscillations of electronspositron pairs created
by the vacuum polarization in an uniform electric field with E < Ec. Our general
treatment, encompassing also the traditional, well studied case of E > Ec , shows
the existence in both cases of a maximum Lorentz factor acquired by electrons
and positrons and allows determination of the a maximal length of oscillation. We
quantitatively estimate how plasma oscillations reduce the rate of pair creation and
increase the time scale of the pair production. These results are particularly relevant
in view of the experimental progress in approaching the field strengths E < Ec.
Speaker: SheSheng Xue
Title: Photoproduction in degenerate electron systems
by Onset of Magnetic Field
Authors: Hagen Kleinert and SheSheng Xue
Abstract:
The energy bands of
a semiconductor are lowered
by an external
magnetic field.
When a field is switched on,
the straightline trajectories near the top of
the
occupied valence
band are curved into Landau orbits and Bremsstrahlung
is emitted until the electrons have settled in their final Fermi distribution.
We calculate the radiated energy, which
should be experimentally detectable, and suggest
that a semiconductor can be cooled
by an oscillating magnetic field.
Speaker: Alexandar F. Zakharov
Title: Dark matter and dark energy of alternative theories of gravity and cosmology
Authors: Alexandar F. Zakharov, F. De Paolis, A. A. Nucita, G. Ingrosso
Abstract: In the last years generalizations of the classical EinsteinHilbert
Lagrangian
were introduced to explain observational phenomena such as the accelerating
Universe, largescale structure, rotation curves etc. Usually, these
approaches
were successful like the standard general relativity (with dark matter and dark
energy).
Recently, gravitational microlensing has been investigated in the
framework of the weak field limit of fourth order gravity theory.
However, solar system data (i.e. planetary periods and light
bending) can be used to put strong constraints on the parameters
of this class of gravity theories. We find that these parameters
must be very close to those corresponding to the Newtonian limit
of the theory. We also discuss constraints on conformal cosmological models
from from cosmological SNe Ia data.
