Speaker: George Alekseev
Title: Interaction of black holes with external gravitational
and electromagnetic fields
Author: George Alekseev
Abstract: The so called "monodromy transform" approach, developed by the author, provides a unified general base for construction of solutions with commuting spacetime symmetries for Einstein, Einstein  Maxwell and some other field equations in General Relativity as well as for the effective actions of some string gravity models. In all cases, this approach gave rise to a reformulation of the symmetry reduced nonlinear field equations in terms of a system of linear singular integral equations on the spectral plane which admit, in particular, formulation of principal algorithms for solution of initial and characteristic initial value problems and an explicit construction of infinite hierarchies of exact solutions with (finitely) arbitrary number of free parameters.
In this communication, some general features of this approach will be outlined. Among different possible applications of this approach (stationary axisymmetric fields, nonlinear interaction of various types of gravitational and electromagnetic waves, dynamics of inhomogeneous cosmological models), we concentrate now on the constructing of solutions for black holes interacting with external gravitational and electromagnetic fields. We present in a simple explicit form the solutions for a Schwarzshild and Kerr black holes immersed in the external asymptotically homogeneous magnetic fields and the solution for a Reissner  Nordstr\"om black hole accelerated by asymptotically homogeneous electric field and describe some related features of the black hole dynamics.
Speaker: Lorenzo Amati
Title: The correlation between peak photon energy and radiated energy in GRB
Author: Lorenzo 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.
Speaker: Volodia Belinski
Title: On the equilibrium between charged masses in General Relativity
Authors: G. Alekseev, V. Belinski
Abstract: An asymptotically flat static solution
of EinsteinMaxwell equations which describes the field of two Reissner
 Nordstrom sources in equilibrium is presented. Very simple analytical
forms were found for the solution as well as for the equilibrium
condition which guarantees the absence of any struts on the symmetry
axis. This condition shows that the equilibrium is not possible for two
black holes or for two naked singularities. However, in the case when
one of the sources is a black hole and another one is a naked
singularity, the equilibrium is possible at some distance separating
the sources. It is interesting that for appropriately chosen parameters
even a neutral Schwarzschild black hole can be "suspended" freely in
the field of a naked singularity, which phenomenon is due to the
repulsive forces produced by a naked singularity.
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 CircumBurst Medium (CBM) 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: Connecting vectors and relativistic strains
Authors: Donato Bini, Andrea Geralico
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 observerdependent 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.
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: Pascal Chardonnet
Title: TBA
Authors: TBA
Abstract: TBA
Speaker: Christian Cherubini
Title: Extracting energy from acoustic black holes
Authors: Christian Cherubini, Simonetta Filippi
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". More in detail we develop an unstability which allows to extract energy from the central engine of the system by imposing a mirror at some distance from the central object.
Speaker: Alessandro Chieffi
Title: The massive stars evolution: the H and He burning phases
Authors: Alessandro Chieffi
Abstract: I will review the properties of massive stars in the H and
He burning phases together to the influence of mass loss on the
properties of these stars
Speaker: Francesco Cianfrani
Title: Particles and fields within a unification scheme
Authors: Francesco Cianfrani, Giovanni Montani
Abstract: we discuss properties of particles and fields in a
multidimensional spacetime, where the geometrization of gauge
interactions can be performed. For instance, in a 5dimensional
KaluzaKlein manifold we argue that the motion of charged spinning
bodies is obtain in a Papapetroulike formulation. For what concern
spinors, we outline how the gauge coupling can be recognized by a
proper dependence on extracoordinates and by the dimensional reduction
procedure. Finally applications to the ElectroWeak model are presented.
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: Roberto De Pietri
Title: Numerical 3D simulation of dynamical instabilities of rotating relativistic self gravitating polytropic mater
Author: R. De Pietri.
Abstract: We present results on dynamical instabilities in rapidly rotating
polytropic selfgravitating matter. Using 3D numerical simulations in
full General Relativity, we analyse the effect of overcriticality on
the development of the barmode instability, the effects of
compactness on the position of the threshold for the onset of the
dynamical barmode instability and the appearance of other dynamical
nonaxisymmetric instabilities beside the barmode one.
By using an extrapolation technique we accurately determine the
threshold for a wide range of compactnesses. Our calculations of the
threshold are in good agreement with the Newtonian prediction and
improve the previous postNewtonian estimates. In addition, we find
that for stars with sufficiently large mass and compactness, the m=3
deformation is the fastest growing one. For all of the models
considered, the nonaxisymmetric instability is suppressed on a
dynamical timescale with an m=1 deformation dominating the final
stages of the instability. The presented results suggest that an
oddmode deformation represents a general and latetime feature of
nonaxisymmetric dynamical instabilities both in full General
Relativity and in Newtonian gravity.
Speaker: Simonetta Filippi
Title: Generalized axisymmetric models of selfgravitating
systems
Authors: Simonetta Filippi, Christian Cherubini, Remo
Ruffini, Alonso Sepulveda
Abstract: Nonhomogeneous axisymmetric models of
selfgravitating 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.
Speaker: Federico Fraschetti
Title: TBA
Authors: TBA
Abstract: TBA
Speaker: Andrea Geralico
Title: Perturbations of a ReissnerNordstrom black hole by a
charged massive particle at rest
Authors: Andrea Geralico, Donato Bini, Remo Ruffini
Abstract: A new perturbative solution describing a twobody system consisting of a ReissnerNordstrom 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.
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: Cristiano Guidorzi
Title: A direct link between the prompt and the late multiband afterglow of a=20
gammaray burst: the case of GRB 070311
Author: Cristiano Guidorzi
Abstract: I present prompt gammaray, early IR/optical, late optical and
Xray observations of the peculiar FRED GRB 070311 discovered by
INTEGRAL. In particular the Hband light curve taken by REM covers the
tail of the gammaray prompt emission and shows two peaks, the second of
which coincides with an enhancement in the gammaray flux. Remarkably the
late optical and Xray afterglow underwent a major rebrightening between
3x10^4 s and 2x10^5 s after the burst with an Xray fluence
comparable with that of the prompt emission. Its time profile can be
described as the combination of a timerescaled version of the prompt
gammaray pulse and an underlying power law. This supports a common
origin for both prompt and late Xray/optical afterglow rebrightening of
GRB 070311 within the external shock scenario. In particular, the late
rebrightening would be the result of a refreshed shock due to a second
slower shell emitted after the first: the former may have generated the
GRB itself, while the latter caught up with the fireball blastwave at late
times and produced the rebrightening.
Speaker: Vahe Gurzadyan
Author: Vahe Gurzadyan
Title: On the dark energy and vacuum fluctuations
Abstract: The value of the dark energy due to relevant vacuum fluctuations will be discussed along with its redshift dependence in comparison with available observational data.
Speaker: Roy Kerr
Author: Roy Kerr
Title: The interior of black holes
Abstract: TBA
Speaker: Massimiliano Lattanzi
Author: Massimiliano Lattanzi
Title: Decaying majoron dark matter and neutrino masses
Abstract: Neutrino masses may arise from spontaneous breaking of ungauged lepton number. Due to quantum gravity effects the associated Goldstone boson  the majoron  will pick up a mass. We determine the lifetime and mass required by cosmic microwave background observations so that the massive majoron provides the observed dark matter of the Universe. The majoron decaying dark matter scenario fits nicely in models where neutrino masses arise a la seesaw, and may lead to other possible cosmological implications.
Speaker: Orchidea Maria Lecian
Title: The role of torsion in fermion interactions
Authors: Orchidea Maria Lecian, Giovanni Montani
Abstract: The different behaviors of vectors and spinors under local spacetime transformations allow one to formulate a gauge theory of the Lorentz group, where suitable bein projections of the contortion field are identified with Lorentz connections. As a result, a propagating torsion field with the spincurrent density as a source is predicted from YangMills equations. Both first and second order approaches are developed, and a comparison with PGT is established.
Speaker: Vanessa Mangano
Title: Swift observations of GRB 060614
Author: Vanessa Mangano
Abstract: GRB 060614 is a remarkable nearby GRB (z=0.125) observed by Swift
with puzzling properties, which challenge current progenitor models:
the lack of any bright supernova down to very strict limits and the
vanishing spectral lags are typical of short GRBs, strikingly at odds
with the long (102 s) duration of this event. However, the burst
presents optical, UV and Xray afterglows in remarkable agreement
with standard jetted fireball models. In particular, spectral analysis
of BAT and XRT data in the overlap time interval and after, show that
the peak energy of the burst decays and crosses the XRT energy band
within 500 s from the trigger. The afterglow shows the first jet break
simultaneously detected in optical, UV and Xrays. Moreover, the UVOT
light curves possibly show evidence of the passage of the injection
frequency across the optical band between 10 and 30 ks from the trigger.
Speaker: Michael Rotondo
Title: Electrodynamics for neutron stars: generalized
analytical solutions
Authors: Michael Rotondo, Vladimir Popov, Remo Ruffini,
SheSheng Xue
Abstract: The relativistic ThomasFermi 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.
Speaker: Kjell Rosquist
Title: Gravitationally induced electromagnetic effects
Author: Kjell Rosquist
Abstract: We discuss the relation between the gravitational and electromagnetic
fields as governed by the EinsteinMaxwell field equations. It is
emphasized that the tendency of the gravitational field to induce
electromagnetic effects increases as the size of the system goes down.
This is because the chargetomass ratio Q/M is typically larger in
smaller systems. For most astrophysical systems, Q/M is << 1 while for a
Millikan oil drop, Q/M ~ 10^6. Going all the way down to elementary
particles, the value for the electron is Q/M ~ 10^21. For subatomic
systems there is an additional phenomenon which comes into play. This is
the fact that the gravitational field, according to general relativity,
tends to become dominated by the spin at distances of the order of the
Compton wavelength. The relevant quantity which governs this behavior is
the ratio S/M^2 where S is the (spin) angular momentum. For an electron
S/M^2 ~ 10^44. Therefore, the gravitational field becomes dominated by
gravitomagnetic effects in the subatomic domain. To analyze this
situation we use the asymptotic structure in the form of the multipole
fields. Some important consequences for the electromagnetic fields of
charged particles with spin are pointed out. In particular, the
gravitational field may induce corrections to the Coulomb field which
can be tested experimentally.
Speaker: Remo Ruffini
Title: The physics of GRBs
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, SheSheng Xue.
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.
Speaker: Costantino Sigismondi
Title: Relativistic Corrections to Lunar Occultations
Author: Costantino Sigismondi
Abstract: Relativistic light bending by solar gravitational field affects timings
of lunar occultations.
The example of Venus occultation of June 18, 2007 is discussed and
preliminary observational results are
compared with JPL and IMCCE ephemerides.
Speaker: Leonardo Testi
Title: Science with ALMA: the cool side of the Universe
Author: Leonardo Testi
Abstract: ALMA is going to be the world leading observatory at millimeter
wavelengths in the coming decades, the project is now in its main
construction phase with early science activities e3nvisaged for 2010 and
full science operations for 2012. In this talk I will review the
concept, science goals and construction status of ALMA.
Speaker: Gregory V. Vereshchagin
Title: On vacuum polarization and plasma oscillations
Authors: Gregory V. Vereshchagin, Remo Ruffini, SheSheng
Xue
Abstract: Vacuum polarization in a strong electric field
results in electronpositron pair creation. We study
collective effects in the pair plasma emerged in this way,
including vacuum polarization itself, backreaction 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 VlasovBoltzmann 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.
Speaker: SheSheng Xue
Title: Energetically favorable electrodynamical
configuration for neutron stars
Author: SheSheng Xue, Vladimir Popov, Michael Rotondo, Remo
Ruffini
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
numberdensities are the same in neutron stars.
