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XXII SIGRAV MEETING
Cefalù, Sept. 12, 18, 2016
List of Abstracts
Andrea ADDAZI (Univ. Aquila/LNGS-INFN)
Antievaporation in Extended theories of gravity
The semiclassical effects of antievaporating black holes can be
discussed in the framework of f(R) gravity. In particular, the BoussoHawking-Nojiri-Odinstov antievaporation instability of degenerate
Schwarzschild-de Sitter black holes (the so called Nariai space-time)
leads to a dynamical increasing of black hole horizon in f(R) gravity.
This phenomenon causes the following transition: emitting marginally
trapped surfaces become space-like surfaces before the effective
Bekenstein-Hawking emission time. As a consequence, BoussoHawking thermal radiation cannot be emitted in an antievaporating
Nariai black hole. Possible implications in cosmology and black hole
physics are also discussed.
Giulio Francesco ALDI (Univ. Salerno)
Contribution of higher order images of accretion disks to
relativistic iron lines in the strong deflection limit
The shape of relativistic iron lines observed in spectra of candidate
black holes carry the signatures of the strong gravitational fields in
which the accretion disks lie. These lines result from the sum of the
contributions of all images of the disk created by gravitational lensing,
with the direct and first-order images largely dominating the overall
shapes. Higher order images created by photons tightly winding around
the black holes are often neglected in the modeling of these lines, since
they require a substantially higher computational effort. With the help of
the strong deflection limit, we present the most accurate semi-analytical
calculation of these higher order contributions to the iron lines for
Schwarzschild black holes. We show that two regimes exist depending
on the inclination of the disk with respect to the line of sight. Many
useful analytical formulae can be also derived in this framework.
Lorenzo AMATI (INAF-IASF Bologna) INVITED SPEAKER
Cosmology with Gamma-Ray Bursts
TBD
L. Angelo ANTONELLI (INAF-OAR/ASI-ASDC Roma) INVITED
SPEAKER
Searching for VHE emission from GW sources with MAGIC.
In this talk I will report on the search for very high energy photons
possibly emitted by GW sources with the MAGIC telescopes. Future
perspectives on this activity with CTA will be also presented.
Paolo ASCHIERI (Univ. Piemonte Orientale) INVITED SPEAKER
Observables and dispersion relations in quantum spacetimes
We study the propagation of massless fields in noncommutative
Minkowski spacetime (jn particular kappa-Minkowski) and single out
energy-momentum observables as the deformed energy-momentum
Hermitian operators that generate the quantum Lie algebra of
translations. They lead to undeformed dispersion relations, in
agreement with a group velocity derivation and contrary to previous
results in the literature. We next turn on a background gravitational field
and observe that the combined effects of non-commutativity and
curvature produce deformed dispersion relations. Aiming at a model for
the analysis of gamma ray burst data we study dispersion relations in
nonocommutative Friedmann–Lemaître–Robertson–Walker cosmology.
Enrico BARAUSSE (IAP/CNRS, France) INVITED SPEAKER
Theoretical implications of gravitational-wave observations
I will review the implications of gravitational-wave observations for tests
of gravitation in the highly relativistic strong-field regime.
Massimo BASSAN (Univ. Tor Vergata Roma, Italy)
TBD
Francesco BECATTINI (Univ. Firenze) INVITED SPEAKER
Thermodynamic equilibrium in relativity and quantum field theory
We address the general features of thermodynamic equilibrium in
special and general relativity within a quantum statistical framework.
The building block of relativistic thermodynamics is the four-temperature
vector β, which can be defined in terms of ideal thermometers and is to
be a Killing vector field at equilibrium. We discuss the quantum
corrections to the ideal stress-energy tensor in general equlibria with
acceleration and vorticity in flat and curved spacetimes.
Tomaso BELLONI (INAF-OA Brera) INVITED SPEAKER
Black Holes and Neutron Stars as Laboratories for Strong Gravity
Binary systems containing a black hole or a neutron star offer the best
possibility to test prediction of General Relativity in the strong field
regime. The plasma stripped from the non-degenerate companion star
reaches the space time in the immediate vicinity of the compact object
and releases strong X-ray emission. The spectral and variability
properties of this emission contain the signatures of predicted effects
such as the presence of an innermost stable orbit and black hole spin.
I discuss the current observational status with particular emphasis onto
sub-second time variability, which constitutes the most direct
measurement of the properties of the plasma accreting onto a collapsed
star. I present recent results that led to a precise measurement of the
spin of a stellar-mass black hole through the measurement of GR
effects from fast time variability.
Stefano BELLUCCI (LNF-INFN Frascati) INVITED SPEAKER
Vacuum Currents from Geometry, Topology and Boundaries
In the present talk we present the results of recent investigations for the
vacuum expectation value of the current density for charged scalar and
fermionic fields in background spacetimes with an arbitrary number of
toroidally compactified spatial dimensions, in the presence of an
external gauge field. Along compact dimensions quasiperiodicity
conditions for the field operators are assumed with general phases.
Three different cases of the local geometry are considered: Minkowski
[1], de Sitter (dS) [2] and anti-de Sitter (AdS) spacetimes [3]. The high
symmetry of the background geometries allowed us to provide closed
expressions for the local characteristics of the vacuum state. We also
discuss the effects induced by the presence of boundaries. The latter
modify the spectrum of the zero-point fluctuations of quantum fields
and, as a result of this, the vacuum expectation values of the current
densities are changed. In the problem with AdS bulk the boundaries
considered can serve as a models for the branes. We will review
applications to the electronic subsystem of cylindrical and toroidal
carbon nanotubes described in terms of a (2 + 1)-dimensional effective
field theory, and to higher dimensional generalizations of the RandallSundrun-type braneworlds with compact dimensions.
[1] S. Bellucci, A. A. Saharian, V. M. Bardeghyan, Phys. Rev. D 82,
065011 (2010); S. Bellucci, A. A. Saharian, Phys. Rev. D 87, 025005
(2013); S. Bellucci, A. A. Saharian, N.A. Saharyan, Eur. Phys. J. C 75,
378 (2015).
[2] S. Bellucci, A.A. Saharian, H.A. Nersisyan, Phys. Rev. D 88, 024028
(2013).
[3] S. Bellucci, A. A. Saharian, V. Vardanyan, JHEP11(2015)092; S.
Bellucci, A. A. Saharian, V. Vardanyan, arXiv: 1512.06569.
Eloisa BENTIVEGNA (INFN Catania) INVITED SPEAKER
Cosmological Numerical Relativity: a status report
Cosmological observations have reached the era of sub-percent
measurements, and their interpretation demands accurate modelling of
even the finest cosmic history details. Furthermore, the first detection of
a gravitational-wave signal, announced in February, opens a new
chapter in the exploration of the elaborate role played by General
Relativity in our Universe. A number of recent studies have addressed
the inclusion of general-relativistic effects in the description of largescale cosmological processes using Numerical Relativity [1-9]; in
particular, the first studies of cosmological spacetimes containing
pressureless fluids with three-dimensional density profiles have now
appeared [10-12]. I will first review the techniques used in these works,
presenting the open-source Einstein Toolkit and its extensions
necessary to build well-behaved simulations of cosmological
spacetimes. I will then illustrate the departures of these exact
spacetimes from the modelling approximations commonly used to
describe the evolution of the late Universe, thereby providing a first
estimate of the systematic errors involved in these approximations.
[1]
http://arxiv.org/abs/arXiv:1204.2411
[2]
http://arxiv.org/abs/arXiv:1204.3568
[3]
http://arxiv.org/abs/arXiv:1306.1389
[4]
http://arxiv.org/abs/arXiv:1306.4055
[5]
http://arxiv.org/abs/arXiv:1404.1435
[6]
http://arxiv.org/abs/arXiv:1409.3476
[7]
http://arxiv.org/abs/arXiv:1409.7953
[8]
http://arxiv.org/abs/arXiv:1501.06918
[9]
http://arxiv.org/abs/arXiv:1509.08354
[10]
http://arxiv.org/abs/arXiv:1511.01105
[11]
http://arxiv.org/abs/arXiv:1511.01106
[12] http://arxiv.org/abs/arXiv:1511.05124
Massimo BIANCHI (Univ. Tor Vergata Roma) INVITED SPEAKER
Fundamental Interactions: one String to rule them all
TBD
Mishra BIVUDUTTA (Birla Inst. Of Tech & Science, Hyderabad,
India)
Cylindrically symmetric cosmological model of the universe in
modified gravity
In this paper, we have constructed the cosmological models of the
universe in a cylindrically space time in the two classes of f(R,T)
modified theory of gravity. The matter field is considered to be in the
form of perfect fluid. It is observed that in the first two classes pressure
and energy density remain the same which reduces to a Zeldovich fluid.
Some physical properties of the constructed models are studied.
Ignazio BOMBACI (Univ. Pisa/EGO) INVITED SPEAKER
Neutron stars: cosmic laboratories to study matter at extreme
densities
Neutron stars, the compact remnants of core-collapse supernova, are
the densest macroscopic objects in the Universe. They represent the
limit beyond which gravity overwhelm all the other forces of nature and
lead to the formation of a black hole. Thus neutron stars are remarkable
natural laboratories that allow us to investigate the fundamental
constituents of matter and their interactions under extreme conditions
that cannot be reproduced in terrestrial laboratories. In this talk, I will
briefly discuss some of the present models to describe the equation of
state of dense strongly interacting matter and their application to
neutron star physics. In particular, I will focus on some open problems
as the so-called hyperon puzzle in neutron stars and the possible
presence of a quark deconfined phase, thus considering the so-called
quark stars. Finally, I will discuss the astrophysical consequences of the
possible conversion process of hadronic stars to quark stars.
Alfio BONANNO (INAF-OA Catania)
Astrophysical implications of the Asymptotic Safety Program in
Quantum Gravity INVITED SPEAKER
The status of the Asymptotic Safety program in QG will be briefly
reviewed. Cosmological and astrophysical consequences for the
physics of the Early Universe and gravitational collapse will be
discussed in detail.
Andrzej BOROWIEC (Wroclaw Univ., Poland)
Starobinsky cosmological model a la Palatini
We discuss Starobinskiy cosmological model in a framework of Palatini
gravity. It appears that such approach provides on the one hand very
good agreement with the present day experimental data as well as an
internal inflationary mechanism driven by type III freeze singularity on
the other hand. A dynamical system analysis indicates similarity to
LCDM model for the late times while singular inflation takes place
before recombination epoch. The talk is based on recent papers with A.
Stachowski, M. Szydlowski and A. Wojnar.
Mounir BOUSSAHEL (Mohamed Boudiaf Univ, Msila, Algeria)
Dark Energy Effect in Quantum Entanglement in Curved Space
Considering the accelerate expansion of the universe, the effect of a
gravitational field of a massive body `'black hole" on the spin
entanglement has been studied for two particles system in a circular
geodesic motion. The concurrence is robust, the effect of the
cosmological constant is that the triplet state is more robust than the
singlet state, not only the effect of the dark energy is evident in both
cases but the robustness of the concurrence is prolonged even around
the black hole.
Marica BRANCHESI (Univ. Urbino)
Multi-messenger Astronomy with
Electromagnetic Radiation
Gravitational
Waves
and
TBD
Enzo BROCATO (INAF-OAR Roma, Italy) INVITED SPEAKER
TBD
Marco BRUNI (Univ, Portsmouth, UK) INVITED SPEAKER
Nonlinear GR effects in structure formation: from approximations
to full numerical relativity simulations
In this talk I will describe progresses in considering general relativistic
effects in the dynamics of structure formation in cosmology. First I will
briefly describe results obtained with a nonlinear post-Friedman
approach, a kind of post-Newtonian formalism, results validated and
extended by others. Then I will focus on recent full numerical relativity
simulations in cosmology. The recent detections of gravitational waves
and of binary black holes have validated the accuracy of numerical
relativity codes that are now publicly available. The application of
numerical relativity to cosmology is in its infancy, but in the next few
years can be a fundamental tool to understand to which extent we can
have reliable predictions from standard newtonian N-body simulations; it
is indeed clear that, to match the precision of future cosmological
measurements, we need theoretical predictions that are not only equally
precise, but also accurate at the same level. I will illustrate the first
results of these numerical relativity simulations, representing the fully
nonlinear GR evolution of perturbations in a Einstein de Sitter
background: 1) back-reaction effects on the overall expansion of the
model seems to be tiny; 2) voids expansion rate is significantly higher
than that of the background and close to that of an open universe; 3)
over-densities can reach turn-around much earlier than predicted by the
standard top-hat model. I will conclude with an outline of future work
that is needed to establish the real significance of these results.
Marta BURGAY (INAF-OA Cagliari) INVITED SPEAKER
Testing GR with the double pulsar
Millisecond pulsars are extremely stable clocks. When in orbit around
another compact object, such as a second neutron star, they can be
used to precisely probe the effects predicted by General Relativity (and
alternative theories). Thirteen years after its discovery, PSR J07373039A/B, the only double pulsar system known and the most relativistic
binary pulsar to date, is the best laboratory to test Einstein's theories in
the strong field regime. In this talk we will review the results obtained in
more than a decade of observations of this unique system, and present
the latest limits obtained.
Luciano BURDERI (Univ. Cagliari)
Quantum clock: A critical discussion on spacetime
We critically discuss the measure of very short time intervals. By means
of a Gedankenexperiment, we describe an ideal clock based on the
occurrence of completely random events. Many previous thought
experiments have suggested fundamental Planck-scale limits on
measurements of distance and time. Here we present a new type of
thought experiment, based on a different type of clock, that provide
further support for the existence of such limits. We show that the
minimum time interval Δ t that this clock can measure scales as the
inverse of its size Δ r . This implies an uncertainty relation between
space and time: Δ r Δ t >G ℏ /c4, where G , ℏ , and c are the
gravitational constant, the reduced Planck constant, and the speed of
light, respectively. We outline and briefly discuss the implications of this
uncertainty conjecture.
Salvatore BUTERA (Heriot-Watt Univ. Edinburgh, UK)
Black-Hole lasing in a spinorial Bose-Einstein condensate
We study the analogue of the Hawking radiation physics in a coherently
coupled two component Bose-Einstein condensate. In practice, we
consider a gas of two level atoms, whose internal states are coupled by
an external laser field. Both for the homogeneous and the harmonically
trapped (quasi-) one-dimensional system we show, by properly tuning
the mean-field coupling constants and the Rabi frequency of the lightatoms interaction, the occurrence of the black-hole lasing effect
respectively in the density and in the spin-density branches of the
fluctuation field. The advantage of considering this set-up relies on the
high controllability of the parameters of the light-atoms interaction in
state-of-the-art cold-atom experiments and on the fact that, coupling the
internal states by a two-photons Raman interaction, the inhomogeneity
of the laser-atom interaction do not locally modify the chemical potential
of the system, which remain homogeneous over all the condensate
without the necessity of opportunely tailoring the external confining
potential.
Mariano CADONI (Univ. Cagliari) INVITED SPEAKER
Thermodynamics and Holography of Gauss-Bonnet Gravity
Gauss-Bonnet gravity is a interesting playground for investigating
thermodynamical and holographic properties of black holes.
We discuss its thermodynamical and holographic properties, with
particular reference to the shear viscosity to entropy ratio in the dual
field theory, focusing on the charged black brane solutions.
Enrico CALLONI (Univ. Federico II Napoli) INVITED SPEAKER
Towards weighing the Vacuum Energy
The Archimedes project is a pathfinder for an experiment for the
measurement of the interaction of vacuum energy and gravitational field
by
weighing
a
suitable
realized
multi-Casimir
cavity.
The main ideas and presnt experimental situations are discussed.
Roberto CAPUZZO-DOLCETTA (Univ. La Sapienza Roma) INVITED
SPEAKER
Compact massive objects in galactic centers
Central regions of galaxies are sites of both violent activity and exotic
objects (super massive black holes, nuclear star clusters). Gravity is the
main engine, able to connect the large (kiloparsec) galactic scale down
to the inner (parsec) scale. In this talk I outline some relevant aspects
of the physics involved.
Mauro CARFORA (Univ. Pavia) INVITED SPEAKER
The Cosmological Back-Reaction Debate
Cosmological Backreaction refers to the influence that density and
curvature inhomogeneities may have on the standard Friedman–
Lemaıtre–Robertson–Walker (FLRW) description of the average
dynamics of the Universe. This is a long standing issue that has
become of some relevance in connection with the Dark Energy problem.
Recently doubts have been put forward as to the actual role of
backreaction in acting like dark energy. In particular, S. Green and R.
Wald have elaborated a formalism according to which the contribution
of backreaction is represented by a trace-free effective energymomentum tensor and cannot mimic a dark energy component. This
has given rise to a lively debate which we overview by discussing the
pros and cons of the Green&Wald formalism.
Roberto CASADIO (Univ. Bologna) INVITED SPEAKER
Black Holes: a window into Quantum Gravity
Black holes are regions of space-time where gravity becomes so strong
as to confine everything. Their existence has been recently confirmed
by direct gravitational wave detection from a binary black hole merger,
however their classical picture shows critical aspects when faced with
the established quantum nature of matter. After reviewing what we think
we know about the gravitational collapse and the special role played by
black holes in the development of a theory of quantum gravity, I will
focus on an effective quantum description of the gravitational radius of
quantum sources as a tool to investigate black hole physics beyond the
classical general relativistic picture, and on the possible effects of
(virtual) soft gravitons in the collapse of baryonic matter. Both analysis
appear to support a corpuscular model of black holes as quantum
extended objects.
Santi CASSISI (INAF-OA Teramo) POSTER
TBD
Leonardo CASTELLANI (INFN Torino) INVITED SPEAKER
The integral form of supergravity
Using integral forms and Poincaré duals, we show how group manifold
actions interpolate between superspace and component supergravity
actions. The example of D=3, N=1 supergravity is treated explicitly.
Bianca CERCHIAI (Centro Fermi,
INVITED SPEAKER
A special root to Born-Infeld Theories
Roma/Politecnico
Torino)
Various n-field non-linear Born-Infeld like theories are constructed which
are self-dual and which feature an on-shell electric-magnetic duality
symmetry. They are obtained from a linear Lagrangian by integrating
out the auxiliary fields through their equations of motion. The potential is
of the type V=Tr(M), where M is a symmetric symplectic matrix
depending on scalar fields, and if the scalar fields span a homogeneous
symmetric space G/H with H a subgroup of a Lie group G and M defines
an embedding of G/H in Sp(2n)/U(n), then the theory exhibits on-shell H
duality invariance. This method allows to associate a non-linear BornInfeld type Lagrangian to any extended supergravity theory based on M
and to explain the form of some previously known Lagrangians with
U(1), U(1) x U(1) and SU(2) on-shell symmetry. A new theory with
SO(n) duality is presented, which can be generalized to a non-Abelian
Born-Infeld theory. Furthermore, there is a parametrization, generalizing
the Euler angles, in which the potential V simplifies significantly due to
its H-invariance, explicitly showing that it depends only on a maximal
torus in the non-compact manifold and that the other coordinates are
flat directions, which play a role similar to Goldstone bosons.
Roberto CIANCI (Univ. Genova) INVITED SPEAKER
Formal calculation and exact Dirac Einstein solutions
We show how formal calculation can be developed and used to exacly
solve gravitational interacting fields equation. In particular we look for
exact interacting solutions of the Dirac Einstein fields. By considering a
massive neutrino field interacting, in a minimal coupling, with the
gravitational filed, we present a discuss some new class of solutions
which are found within the class of non empty axially-symmetric metric.
Riccardo CIOLFI (UNiv. Trento) INVITED SPEAKER
TBA
Monica COLPI (Univ. Milano Bicocca) INVITED SPEAKER
A Gravitational Universe Full of Binary Black Holes in the LISA Era
Binary black holes occupy a special place in our quest for
understanding the formation and evolution of galaxies along cosmic
history. If massive black holes grow at the center of pre-galactic
structures that experience a sequence of merger episodes, then
"binary" black holes inescapably form. If they end coalescing inside the
remnant galaxy, then they become the most powerful sources of
gravitational waves in the universe, visible out to very large redshifts. I
will shortly describe how binary black holes form and coalesce and the
key feature of their gravitational wave signal. Finally I will comment on
the impact of LISA science on the astrophysics of black hole formation
and evolution.
Giovanni COVONE (Univ. Federico II Napoli)
The Kilo Degree Survey: new constraints on the cosmological
parameters from tomographic weak gravitational lensing
The Kilo Degree Survey (KiDS) is an on-going VST survey aimed at
cover 1500 square degrees in the optical bands with excellent image
quality. I will present the analysis of the shear measurements over the
first 450 square degrees, the blind cosmology analysis, the new
contraints on the cosmological parameters and the substantial
discordance in the full parameter space found with respect to the Planck
2015 results.
David COWARD (Univ. Western Australia) INVITED SPEAKER
Australian participation in the first EM follow-up of gravitational
wave sources: from radio to optical
TBD
Elena CUOCO (EGO Pisa) INVITED SPEAKER
Strategy for signal classification to improve data quality for
Advanced Detectors gravitational-wave searches
Noise of non-astrophysical origin contaminates science data taken by
the Advanced Laser Interferometer Gravitational-wave Observatory and
Advanced Virgo gravitational-wave detectors. Characterization of
instrumental and environmental noise transients has proven critical in
identifying false positives in the first aLIGO observing run O1. In this
talk, we present three algorithms designed for the automatic
classification of non-astrophysical transients in advanced detectors.
Principal Component Analysis for Transients (PCAT) and an adaptation
of LALInference Burst (LIB) are based on Principal Component
Analysis. The third algorithm is a combination of a glitch finder called
Wavelet Detection Filter (WDF) and machine learning techniques for
classification.
Nandi DEBOTTAM (Indian inst. Of Science Educa & Research,
India)
Complete Hamiltonian analysis of cosmological perturbations at
all orders
Cosmological perturbation theory is currently a preferred mathematical
procedure to compare the equations of gravity with precise
observations. However, due to the difficulties in interpreting gaugeinvariance and invertibility in Hamiltonian formalism, there is no
consistent and generalized Hamiltonian analysis for cosmological
perturbation theory at any order for any kind of model of gravity. In this
work, using a simple model, we provide a simple mathematical
approach to deal with all the difficulties to obtain a consistent
Hamiltonian formalism and extend the approach to canonical scalar
field. We show that our approach can be applied to any order of
perturbation for any first order derivative fields. We also apply our
approach to Galilean scalar field model and show that, there is no extra
degrees of freedom, as expected, at every order of perturbation and
obtain all consistent equations of motion. We compare and contrast our
approach to the Lagrangian approach (Chen et al[2006]) for extracting
higher order correlations and show that our approach is quick and
robust and can be applied to any model of gravity and matter fields
without invoking slow-roll approximation. Finally, we show that, by
introducing a new phase-space variable, it is also possible to extend the
same formalism for generalized non-canonical scalar fields.
References:
1. D. Nandi and S. Shankaranarayanan, Complete Hamiltonian analysis
of cosmological perturbations at all orders, JCAP 1606 (2016), no. 06
038,arXiv:1512.02539
2. D. Nandi and S. Shankaranarayanan, Complete Hamiltonian analysis
of cosmological perturbations at all orders II: Non-canonical scalar field,
arXiv:1606.05747
Fernando DE FELICE (Univ. Padova)
Chronology protection in the Kerr metric
(Authors: Donato Bini and Fernando de Felice, Gen. Rel. & Grav.
47 (2015) 131)
We show that causality violation in a Kerr naked singularity spacetime is
prevented by the existence of radial potential barriers. We extend to the
family of vortical non-equatorial null geodesics confined on hyperboloids
with constant latitude (Boreal orbits) previous results concerning timelike ones (Calvani et al.; Gen. Rel. & Grav. 9: 155, 1978) showing that
within this class of orbits the causality principle is rigorously satisfied.
Maria Felicia DE LAURENTIS (Goethe Univ. Frankfurt, Germany)
Pulsar dynamics in general black-hole spacetimes: spherically
symmetric case
TBA
Roberto DE PIETRI (Univ. Parma/INFN) INVITED SPEAKER
The EinsteinToolikt at work: Simulating the Physics of Equal and
Unequal Mass Binary Neutron Star Mergers Using Public Codes
After the succesfull detection of the gravitational wave signals emitted
by binary black holes mergers observed by the LIGO/Virgo collaboration
the modelling of the gravitational wave signal emitted by compact binary
sources will play a prominent role. The next target will be the
observation emitted during the process of Binary Neutron Star (BNS)
mergers that were the the primary expected sources for the
LIGO/VIRGO observatory. Fully General Relativistic simulations of BNS
coalescence and merger started in 1998 but now, thanks to the
development of collection of free software like the Einstein Toolkit (and
the LORENE library to generate initial data) it is possible to openly
simulate such systems where numerical relativity is almost the only
available tool. The use of open and publically available simulation toolkit
allows other researchers to reproduce the obtained data and to check
the details of the employed methods. We present results for threedimensional simulations of BNS mergers dynamics (in full general
relativity) for the late inspiral stage and the post-merger up to ∼50 ms
after the system has merged. We report here results for the strength of
the gravitational wave (GW) signal and its dependence on the equation
of state (EOS), the total ADM mass, and the mass ratio of the two Stars.
The present results are based on a semi-realistic description of the EOS
that it is represented by seven-segment piece-wise polytropic and a
thermal component with Γth=1.8.
Antonino DEL POPOLO (Univ. Catania) INVITED SPEAKER
The small scale problems in the standard cosmology
Despite the fact that the LAmbdaCDM model is often referred to as
"concordance model", to emphasize that its predictions are in
agreement with current observations, both of the nearby universe and
the early universe, some discrepancy with observations has emerged
on scales from a few kpc to tens of pc. Examples of the quoted tension
are: the missing satellite problem, the too big to fail problem, and the
cusp/core problem. While numerical simulations universally produce a
cuspy density profile, observed rotation curves of dwarf spiral and low
surface brightness (LSB) galaxies give strong indication that the shape
of the density profile at small scales is significantly shallower than
profiles found in numerical simulations. The quoted discrepancy
between simulations and observations has become known as the
Cusp/Core problem. In this talk, I review the problem and discuss some
solutions.
Luca DEL ZANNA (Univ. Firenze) INVITED SPEAKER
Magnetized neutron stars: GR modeling and interaction with the
environment
Magnetized neutron stars have always been among the main
characters in high-energy astrophysics, since the discovery of pulsars
almost 50 years ago and up to the recent models predicting fastspinning magnetars as the engines of Gamma-Ray Bursts. In this talk I
will describe the research carried out in Firenze: from the modeling of
such compact objects in general relativity, to the simulations of the
interaction of pulsar winds with the external environment.
Simone DELL’AGNELLO (LNF-INFN Frascati) INVITED SPEAKER
The Moon and Mars as Test Bodies for General Relativity
We developed next-generation laser retroreflectors for the exploration
and science of the Earth-Moon and Mars systems in the framework of
the INFN-NASA/SSERVI Affiliation membership. We will describe
payload design/construction/test, space exploration goals and, finally,
future prospects to test General Relativity (GR) and new gravitational
physics in the Mars and Earth-Moon system. We will describe INRRI
(INstrument for landing-Roving laser Retroreflector Investigations)
deployed on ESA’s ExoMars Schiaparelli lander and designs for
PANDORA (Phobos ANd DeimOs laser Retroreflector Array) and their
gravitational science and exploration goals. PANDORA will be observed
Mars orbiters with laser ranging capabilities, like NASA’s LADEE and/or
LRO for the Moon. By tracking the Phobos orbit we can reconstruct the
position of the Mars center of mass and with that, test GR.
We developed a large, single, next-generation retroreflector
(MoonLIGHT, Moon Laser Instrumentation for General relativity High
accuracy Tests). Since it is unaffected by the lunar librations that
currently limit the accuracy of Lunar Laser Ranging (LLR) to
Apollo/Lunokhod reflectors, MoonLIGHT will support significantly
improved measurements by ground stations of the International Laser
Ranging Service (ILRS). MoonLIGHT will provide accurate
determination of landing sites, of rover positioning during exploration
and long-term Moon georeferencing. MoonLIGHT will also support
precision tests of GR (improved up to a factor 100): violation of the
Weak and Strong Equivalence Principle (WEP/SEP); measurement of
the PPN parameter beta; time variations of the gravitational constant
Gdot/G; deviations from the inverse-square force-law; accurate
measurement of the geodetic precession. We will report also possible
test of new gravitational theories, like Non-Minimally Coupled Gravity.
We will also report studies and R&D to test new effective Quantum
Gravity theories (predicted by theorists of INFN-Naples, G. Esposito
and E. Battista) by means of laser retroreflectors deployed in the
Lagrangian
points
of
the
Earth
Moon
system
R&D (science) on these laser retroreflector payloads is supported by
INFN-CSN5 (INFN-CSN2) and is fully synergetic with the goals of the
INFN-NASA/SSERVI Partnership. Laser retroreflector performance will
be characterized at the SCF_Lab (Satellite/lunar/gnss laser
ranging/altimetry Cube/microsat Characterization Facilities Laboratory),
a unique and dedicated infrastructure of INFN-LNF, in Frascati (Rome),
Italy, (www.lnf.infn.it/esperimenti/etrusco/). Finally, we will discuss
mission opportunities
retroreflectors.
to
deploy
these
next
generation
laser
Massimo DELLA VALLE (INAF-OA Capodimonte) INVITED
SPEAKER
TBD
Antonaldo DIAFERIO (Univ. Torino) INVITED SPEAKER
The caustic technique: the wide-angle tool for disclosing cluster
formation
I review the state of the art and future developments of the caustic
technique, a method for estimating the mass of galaxy clusters, both in
their virial and outer regions, based on the distribution of galaxies in
redshift space. The caustic technique has been proved to recover mass
profiles of simulated clusters with an accuracy smaller than 10% out to
three virial radii, from cluster catalogs with realistic galaxy density. The
technique has been applied to more than 130 real clusters from the
CAIRNS, CIRS and HeCS surveys. As a method to identify cluster
members, up to the same large radii, the technique prunes interlopers
yielding samples with high completeness (~95%) and low contamination
(~8%). One of the byproducts of this technique is the creation of a
binary tree that arranges the galaxies hierarchically and provides
information about the cluster dynamics and its substructures. The
caustic technique recovers 50% of the real substructures of the cluster,
an unprecedentedly large successful rate in realistic situations. I finally
discuss how we can apply this technique to measure the mass growth
of galaxy clusters and constrain the theory of gravity.
Antonio DI DOMENICO (Univ. La Sapienza Roma) INVITED
SPEAKER
Precision tests of CPT symmetry and Quantum coherence with
entangled neutral K mesons in the search for Quantum Gravity
effects
Even though CPT symmetry appears to be experimentally respected in
Nature, with a very solid theoretical foundation in the well known CPT
theorem, tiny CPT violation effects could be justified in the framework of
a quantum theory of gravity with non trivial space-time topologies, in
some cases implying a loss of coherence in single and entangled
quantum states. Entangled neutral K mesons produced in phi meson
decays constitute a very special quantum system, which demonstrate,
in the most impressive manner, a number of spectacular quantum
phenomena. This system appears specially suited for testing the basic
principles of Quantum Mechanics and CPT symmetry, thanks to its
extreme sensitivity to possible CPT violation and decoherence effects
and the subtle interplay between entanglement and discrete
symmetries. So far no deviation from the expectations of CPT
symmetry and Quantum Mechanics is observed, while the precision of
the measurements, in some cases, reaches the interesting Planck scale
region, where CPT violation effects driven by quantum gravity might
show up. Prospects for this kind of experimental studies at the KLOE-2
experiment at DAFNE will be presented.
Sperello DI SEREGO ALIGHIERI (INAF-OA Arcetri) INVITED
SPEAKER
Cosmic Polarization Rotation: testing the foundations of General
Relativity
An important reason for searchig for Cosmic Polarization Rotation
(CPR), i.e. a rotation in vacuum of the plane of polarization for radiation
traveling across a large fraction of the universe, is that it provides a test
for the Einstein equivalence principle (EEP). Therefore, a null CPR
would increase our confidence on General Relativity which is based on
the EEP. I shall review recent constraints on the CPR, including those
form Planck, which are all consistent with a null CPR, and discuss
future propects for improving the constraints or detecting CPR.
Angela Di VIRGILIO (Univ. Pisa)
GINGER (Gyroscopes IN General Relativity) is a proposal aiming at
measuring the Lense-Thirring effect with an experiment based on Earth.
It is an array of ringlasers, which are the most sensitive inertial sensors
to measure the rotation rate of the Earth. After reviewing the importance
of light as a probe for testing the structure of space-time, we describe
the GINGER project. GINGER is based on an array of large size ringlasers able to measure the de Sitter and Lense-Thirring effects. The
instrument will be located inside the underground laboratory of
GranSasso of INFN, in Italy. We describe the preliminary actions and
measurements already under way and present the full road map to
GINGER. The prototypes GP2 and GINGERino are described and the
preliminary results reported
Marco DRAGO (AEI-MPG Hannover, germany) INVITED SPEAKER
The beginning of the gravitational wave era
On September 14th and December 26th, LIGO detectors registered the
first gravitational waves. The signal were confirmed to be both produced
by binary black hole system. This talk will present the details of the two
observation.
Vladimir DZHUNUSHALIEV (Al-Farabi-KazNU) INVITED SPEAKER
Compact and extended objects from self-interacting phantom
fields
We investigate localized and extended objects for gravitating, selfinteracting phantom fields. This study covers phantom balls, traversable
wormholes, phantom cosmic strings, and phantom domain walls
supported by phantom fields. These four systems are solved
numerically and we try to draw out general, interesting features in each
case. In each of the four systems we find regions of the parameters
where there is a balancing between the tendency of gravity to collapse
the system and the tendency of the phantom fields to disperse the
system.
Giampiero ESPOSITO (INFN Napoli) INVITED SPEAKER
Solar System Dynamics in General Relativity: a Modern
Perspective
TBD
Viviana FAFONE (Univ. Tor Vergata Roma) INVITED SPEAKER
Sensitivity evolution of interferometric detectors and GW
astronomy
The first observation of gravitational waves, achieved on September 14,
2015, opened a new frontier of the observational astrophysics and a
new tool for fundamental physics. The capabilities of this new tool will
grow up in the forthcoming years, fostered by the increasing sensitivity
of gravitational wave interferometers. The talk will discuss the
perspectives in the field with a focus on the possible evolution of
interferometric detectors.
Valeria FERRARI (Univ. La Sapienza Roma) INVITED SPEAKER
Gravitational waves after the first detection: perspectives for
fundamental physics and astrophysics
The recent detection by the LIGO interferometers of the gravitational
wave signals emitted by two (possibly three) coalescing black hole
binaries, provides an entirely new instrument to observe and investigate
the universe we live in, challenging or confirming our beliefs on several
crucial issues; how does gravity behave in the strong field regime, as
near a black hole horizon, how does matter behave at the supranuclear
densities which are typical of the inner core of neutron stars; how do
gravitating structures evolve to form compact objects which eventually
produce binary coalescence as those which have been, or will be,
observed. These and other issues, will be illustrated and discussed.
Francesco FERRARO (UNiv. Bologna) INVITED SPEAKER
The dynamical evolution of star clusters as traced by Blue
Stragglers
Galactic Globular Clusters are the only cosmic structures able to
undergo nearly all the physical processes known in stellar dynamics
(such as: gravothermal instability, violent relaxation, mass segregation,
dynamical friction, energy equipartition, 2-body collisions, binary
formation and heating) over a time-scale shorter than the age of the
Universe. In this talk I’m going to discuss these phenomena by using an
anomalously massive class of stars (the so-called Blue stragglers) as
gravitational test particles
Emilio FIORDILINO (Univ. Palermo)
Harmonic emission from reduced dimensionality systems
2015 was designated as the international year of the light to
acknowledge the prodigious progress in the comprehension of the
nature and sources of light. Laser is among the most brilliant source of
radiation of the galaxy, for today it can have peak intensity as large as I
= 10^20 W/cm^2. The interaction of a strong eld of frequency I_L with
the matter has unveiled new laser induced eects. Among these we
focus our attention on high order harmonic generation (HHG). Atoms
and molecules acted upon by a strong eld scatter radiation whose
spectrum is composed by a broad plateau of odd harmonics of !L. The
origin of the radiation is to be sought in the large acceleration of the charges which is non linear in the eld-matter interaction
energy. The detected plateau can be as large as w_M = 5000w_L
indicating that a molecule can be used as a tool for converting radiation
from the infrared or optical part of the spectrum to the XUV regime.
Modern technology permits the fabrication of mesoscopic materials
extending along one or two spatial dimension more that the other(s) and
that can be considered as reduced dimensionality systems (RDS); this
description is possible because the modes pertaining to the small
dimension are energetically very separated and can be considered as
frozen. Well known geometrical simmetries make fullerene, graphene,
quantum dots and rings as perfect RDS and allow striking simplications
of the theoretical treatment unthinkable in simpler systems. We will
show that these carbon allotropes are attractive media for the ecient
generation of harmonics.
Plamen FIZIEV (Joint Inst. Of Nuclear research, Dubna, RUSSIA)
New physics in GW150914
TBA
Antonia Micol FRASSINO (FIAS & Goethe Univ. Frankfurt,
Germany)
Phase Transitions in GR
TBD
Marialuisa FRAU (Univ. PISA/EGO) INVITED SPEAKER
Exact results in N=2 Super Yang-Mills Theories
We study the non-perturbative behaviour of superconformal gauge
theories with rigid N=2 supersymmetry in four dimensions, and discuss
the relation between their S-duality properties and the possibility of
computing exact quantum observables. For these theories in fact, the
prepotential, that encodes the low-energy effective dynamics on the
Coulomb branch of moduli space, obeys a modular anomaly equation
whose validity is related to S-duality. The recursion relations that follow
from the modular anomaly equation allow one to write the prepotential
in terms of (quasi)-modular forms, thus resumming all instanton
contributions. These results can be checked against the microscopic
multi-instanton calculus in the case of classical algebras, but are valid
also for the exceptional algebras, where direct computations are not
available. We also comment on the extensions of these results to the
computation of chiral correlators.
Filippo FRONTERA (Univ. Ferrara) INVITED SPEAKER
Investigating the physics behind the Ep-intensity correlation in
GRBs through the time-resolved analysis
TBD
Noemi FRUSCIANTE (IAP Paris)
Testing dark energy and modified gravity models with the effective
field theory formalism
Given the wide sample of dark energy and modified gravity models
(DE/MG) that address late time accelerated scenario and the high
precision data (WMAP, PLANCK, SDSS, EUCLID in the near future), it
becomes crucial to test DE/MG theories against data on large scales.
In the quest of a model independent parametrization for gravity theories,
the effective field theory formalism (EFT) has been applied to the
phenomenon of cosmic acceleration. It is developed using a
perturbative approach in which an extra scalar degree of freedom
appears only at the level of perturbations. I will present the
implementation of this framework into CAMB/CosmoMC creating, what
we dubbed, EFTCAMB/EFTCosmoMC. These patches allow to test
gravity theories with the most recent data releases. To illustrate the use
of these patches, I will show some results. Moreover, I will present a
thorough stability analysis of modified gravity theories in EFT language
when the coupling to matter fields is considered.
Remo GARATTINI (Univ. Bergamo) INVITED SPEAKER
Aspects of Gravity's Rainbow
Quantum Field Theory is plagued by divergences in the attempt to
calculate physical quantities. Standard techniques of regularization and
renormalization are used to keep under control such a problem. In this
talk we would like to use a different scheme based on Gravity's
Rainbow (GRw)to remove infinities appearing in one loop approximation
in contrast to what happens in conventional approaches. In particular,
we apply GRw scheme to the computation of the entropy of a
Schwarzschild black hole from one side and the Zero Point Energy
(ZPE) of the graviton from the other side. The graviton ZPE is
connected to the cosmological constant by means of of the WheelerDeWitt equation.
Fabio GARUFI (Univ. Federico II Napoli)
Probing newborn population of BH/NS tied to Long Gamma Ray
and Gravitational Wave Bursts
In this work we present a procedure to infer the mass of progenitors and
outcome of core-collapse Gamma Ray Bursts (GRB), starting from the
observed energy E_GRBiso emitted isotropically and considering the
associated emission of Gravitational Waves (GW) E_GW in the different
phases. Without making any assumption, we consider a purely
empirical energy balance exclusively in GW energy with a GW emitting
oblate progenitor, the energy emitted in GW during the GRB phase and
the GW energy emitted by the residual object after the GRB (the
remnant). We take a sample of 237 Long GRB, and use an hybrid
Montecarlo procedure to explore, for each of them, a region of possible
solutions of E_GW as a function of the masses, radii, oblateness,
rotation frequencies of progenitor and remnant and the fraction of
energy k emitted as GW by the GRB.
Bruno GIACOMAZZO (Univ. Trento) INVITED SPEAKER
High-Mass Magnetized Binary Neutron Star Mergers and Short
Gamma-Ray Bursts
TBD
Roberto GIAMBO’ (Univ. Camerino) INVITED SPEAKER
Nonlinear techniques in the study of cosmological dynamics
Some of the mathematical methods exploited in literature, allowing to
get information on the asymptotic behavior of cosmological models with
different matter sources, are reviewed here. In case of ever expanding
cosmologies, the eventually dominating source type can be identified.
For cosmologies leading to a spacetime singularity, the formation of an
event horizon is investigated.
Adalberto GIAZOTTO (INFN Pisa) INVITED SPEAKER
Advanced Virgo and LIGO and the worldwide search for
gravitational waves
Technological efforts of Virgo and LIGO detectors, which led to the
detection of the Gravitational Wave event, will be presented.
Gabriele GIONTI (Specola Vaticana)
Cosmologies of the Planck-Era from Lorentzian Renormalization
Group for Quantum Gravity
Homogeneous and isotropic cosmologies of the Planck-era are studied
taking quantum gravitational effects into account. The cosmological
evolution is obtained from a renormalization – group improvement of the
classical ADM Lagrangian, using a class of beta-functions obtained with
a Lorentzian formulation of the re-normalisation group. The properties of
the solutions are discussed, and the corresponding Hamiltonian
analysis is presented.
Andrea GIUGNO (LMU Munich, Germany)
A corpuscular model for Quantum Black Holes
A quantum mechanical description of an event horizon supports some
features of BEC models of black holes. The Klein-Gordon equation for a
toy graviton field coupled to a static matter current classically
reproduces the Newtonian potential, while the corresponding quantum
state is given by a coherent superposition of scalar modes. When N
such bosons are self-confined in a volume the size of their
Schwarzschild radius, the spectrum of these system is formed by a
discrete ground state and a continuous Planckian distribution at the
Hawking temperature representing the radiation. Assuming the latter is
due to internal scattering, the N-particle state can be collectively
described by a single-particle wave-function. The partition function
follows together with the usual entropy law, with a logarithmic correction
related to the Hawking component. The backreaction of radiating modes
is also shown to reduce the Hawking flux, eventually stopping it.
Leonardo GUALTIERI (Univ. La Sapienza Roma) INVITED
SPEAKER
Testing general relativity with gravitational waves
electromagnetic waves
and
General relativity has passed all weak-field tests with flying colours, but
- before September 14, 2015 - it had hardly been tested in the strongfield regime. Gravitational wave observations from present and future
interferometric detectors, together with observations from upcoming
large-area X-ray telescopes, can tell us if general relativity gives also an
accurate description of the strong-field regime of the gravitational
interaction. I will discuss how some of the simplest modifications of
general relativity, which can be tested by looking at the signals emitted
in astrophysical processes such as the coalescence of compact binaries
and quasi-periodic oscillations in accretions disks.
Gianluca GUIDI (Univ. Urbino) INVITED SPEAKER
Detection of Gravitational Waves from Binary Black Hole merger
During the first observational run of the Advanced LIGO detectors, from
September 12, 2015 to January 19, 2016, two signals, GW150914 and
GW151226, were unambiguously detected with a significance of greater
than 5σ over the observing period. They were identified as coming from
binary black hole mergers at cosmological distance. The detection
made use of several analysis method to extract the signals from the
noise background; here we report of the matched-filter searches
targeting binary coalescences during this first observational run
and the prospect for the next observing runs.
Francesco HAARDT (Univ. Insubria) INVITED SPEAKER
Dynamics of massive black hole triplets in galactic nuclei
Massive black-hole binaries (MBHBs) are thought to be the main source
of gravita- tional waves (GWs) in the low-frequency domain surveyed by
ongoing and forthcom- ing Pulsar Timing Array campaigns and future
space-borne missions, such as eLISA. However, many low-redshift
MBHBs in realistic astrophysical environments may not reach
separations small enough to allow significant GW emission, but rather
stall on (sub)pc-scale orbits. This “last-parsec problem” can be eased
by the appearance of a third massive black hole (MBH) – the “intruder”
– whose action can force, under certain conditions, the inner MBHB on
a very eccentric orbit, hence allowing intense GW emission eventually
leading to coalescence. A detailed assessment of the process,
ultimately driven by the induced Kozai-Lidov oscillations of the MBHB
orbit, requires a general relativistic treatment and the inclusion of
external factors, such as the Newtonian precession of the intruder orbit
in the galactic potential and its hardening by scattering off background
stars. In my contribution, I will discuss a recent effort aimed at tackling
this problem, based on an original three-body Post-Newtonian (2.5PN)
code framed in a realistic galactic potential.
Alexander KAMENSHCHIK (Univ. Bologna/INFN) INVITED
SPEAKER
Some aspects of anisotropic cosmologies
We consider the precession of a Dirac particle spin in some
anisotropic Bianchi universes. This effect is present already in the
Bianchi-I universe. We discuss in some detail the geodesics and the
spin precession for both the Kasner and the Heckmann-Schucking
solutions. In the Bianchi-IX universe the spin precession acquires the
chaotic character due to the stochasticity of the oscillatory approach
to the cosmological singularity. The related helicity flip of fermions
in the very early Universe may produce the sterile particles
contributing to dark matter. Besides, we study the behaviour of the
Bianchi-II universe in the presence higher spatial curvature terms in
the framework of the Horava-Lifshitz gravity. We derive the rules of the
changes of the Kasner indices for this model.
Luca IZZO ( Univ. La Sapienza Roma/ICRA) INVITED SPEAKER
Novae as Lithium factories in the Milky Way: first evidences
TBD
Gaetano LAMBIASE (INFN Salerno) INVITED SPEAKER
Two-field inflation in early Universe
A two-field inflation model, where inflaton field has a non-canonical
kinetic term due to the presence of a moduli/dilaton field, is discussed. It
is shown that in such an inflation model the quartic and quadratic
inflaton potentials, which are otherwise ruled out by the present PlanckKeck/BICEP2 data, yield scalar spectral index and tensor-to-scalar ratio
in accordance with the present data. Such a model yield tensor-toscalar ratio of the order of 0.01 which is within the reach of B−mode
experiments like Keck/BICEP3, CMBPol and thus can be put to test in
the near future.
Adele LA RANA (Univ. La Sapienza Roma, Italy)
Looking for coincidences: the birth of gravitational wave detection
in Italy and the beginning of the first International detector
networks
The first projects for gravitational wave (GW) detection in Italy were
born in 1971 at the Institute of Physics “Gugliemo Marconi” in Rome
and at the European Space Research Institute (ESRIN) in Frascati. The
key figures promoting the new research activity were: in Rome, Edoardo
Amaldi and his young assistant Guido Pizzella; in Frascati, Donato
Bramanti and Karl Maischberger, collaborating with the theoretical
physicist Bruno Bertotti. The interest in GWs had been swiftly growing in
the scientific community since the end of 1960s, stimulated by the
papers by Joseph Weber, claiming with increasing confidence to have
detected gravitational radiation. Furthermore, the development of
relativistic astrophysics and especially the discovery of pulsars in 1968
provided attractive candidates as GW sources. In Rome, synergies and
collaborations between relativistic mathematicians and physicists had
been established during the ‘60s, following the new attitude of the
international scientific community towards Einstein’s theory of
gravitation: the reborn interest in experimental tests of GR and its return
from mathematical research to physical investigation (the so-called
Renaissance of GR). The GW group in Rome aimed at building a
cryogenic resonant bar detector, using the recently invented technology
of Superconducting Quantum Interference Devices (SQUID) to amplify
the signal of the resonant transducer. Instead, the ESRIN team rapidly
set up a room temperature detector, as the ones used by Weber in the
late Sixties. Both groups established collaborations for coincidence
analysis. The activity of the Rome group started as a joint endeavor with
the teams of William Fairbank at Stanford University and the team of
William Hamilton at Louisiana State University, envisaging the
construction of three cryogenic detectors in the three locations.
The ESRIN antenna worked in coincidence with the room temperature
detector located at the Max Planck Institute for Physics and
Astrophysics in Munich.
Frederic LASSIAILLE
Simplified three elements theory
In this paper, S.T.E.T. (Simplified Three Elements Theory), an
alternative theory to dark matter, is presented. It is based on a
modification of Newton’s law. This modification is done by multiplying a
Newtonian potential by a given factor, which is varying with local
distribution of matter, at the location where the gravitational force is
exerted. With this new equation the model emphasizes that a
gravitational force is roughly inversely proportional to mass density at
the location where this force is applied. After presentation of the model,
comparison with experimental data is quickly surveyed. The first result
is the following. The simple mechanism presented above allows to solve
straightforwardly the following issues: virial theorem mystery, the bullet
cluster (“1E 0657-56” galaxy clusters) issue, the strong relative velocity
of its sub-clusters, the value of cosmological critical density, the fine
tuning issue, and expansion acceleration. Nucleosynthesis is not
explained and would require a different model for radiation era. But a de
Sitter Universe is predicted, this means that the spatial curvature, K, is
0, and today’s deceleration parameter, q, is -1. The predicted time since
last scattering is 68 h-1Gyr. With this value STET explains
heterogeneities of large scale structures and galaxy formation. Each
kind of experimental speed profiles are retrieved by a simulation of a
virtual galaxy. In the simulations, ring galaxies are generated by STET
dynamic itself, without the help of any particular external event. By itself
the model claims that a modification of Newton’s law might produce
better results than what dark matter does.
Marco LIMONGI (INAF-OAR Roma, Italy) INVITED SPEAKER
TBD
Fedele LIZZI (Univ. Federico II Napoli) INVITED SPEAKER
The inconstant constants
TBD
Luca LUSANNA (INFN Firenze) INVITED SPEAKER
Dark matter: a problem in relativistic metrology?
I make a short review of the existing possibility to explain the presence
of dark matter (or at least of part of it) as a relativistic inertial effect
induced by the non-Euclidean nature of the 3-spaces. After a
Hamiltonian Post-Minkowskian (HPM) linearization of canonical ADM
tetrad gravity with particles, having equal inertial and gravitational
masses, as matter, followed by a Post-Newtonian (PN) expansion, we
find that the Newtonian equality of inertial and gravitational masses
breaks down and that the inertial gauge York time produces an
increment of the inertial masses explaining at least part of what is called
dark matter in all its astrophysical signatures.
Naulak MALSAWMTLUANGI (Univ. of Hyderabad, India)
Inflation and the BB-mode correlation spectrum of the Cosmic
Microwave Background from massive gravity
Graviton, which is commonly believed to be massless, is endowed with
mass and hence, the primordial gravitational waves are considered to
be massive and are placed in the squeezed vacuum state. The
corresponding BB-mode correlation angular power spectrum of the
cosmic microwave background is obtained for various slow roll inflation
models. The gravitational waves are also placed in thermal state in
addition to the squeezed vacuum state. The angular power spectrum for
each model is compared with the limit of BICEP2/Keck and Planck joint
analysis data.
Stefano MANCINI (Univ. Camerino) INVITED SPEAKER
On relativistic quantum information
Relativistic quantum information is a new promising field that aims at
understanding how general relativity can affect quantum information
processing. In this context we first show how entanglement, a key
quantum information resource, naturally arises in cosmological models
like Robertson–Walker spacetime, thanks to the mechanism of particles
and anti-particles production from the vacuum. We also put forward the
possibility of using entanglement to infer about cosmic parameters. Next
we consider communication through the dynamics of quantum systems
under Robertson–Walker spacetime and find that the noise imparted to
them is equivalent to an amplitude-damping channel. We then
determine the capacity region for communicating classical and quantum
information. This is equivalent to evaluating the maximal amount of
information preserved during the evolution of the universe, hence it can
provide a novel avenue for bounding our knowledge about the origin of
the universe.
Nazzareno MANDOLESI (Univ. Ferrara) INVITED SPEAKER
The Planck Legacy and Future Perspectives
I will discuss highlights from the recent Planck 2015 release and
present the most stringent bounds to date on a widely accepted
cosmological picture, including the latest results from the joint
Planck/Bicep effort on the quest for primordial gravitational waves. The
LCDM model withstood a wide collection of tests at increasing precision
over the last decade and has, with the latest Planck results, gained
further strength. At the same time, we still see small anomalies in the
data that may be simply due to tiny systematics or hint for new physics.
I will briefly review CMB future experiments from ground, balloons and
space in the framework of scientific, technical and programmatic
constraints.
Houda MANSOUR (UNiv. Blida, Algeria) POSTER
Applications in f(R) gravity
Latest cosmological observations show that the universe is undergoing
an accelerating expansion. Several theories were proposed to explain
that acceleration: ΛCDM (Λ accounts for dark energy and CDM is the
cold dark matter), inflationary models. Despite their success, these
theories fail in describing some other phenomenon emerging in
astrophysics cosmology, and high energy physics. So, several
extensions to the theory of gravitation were proposed aiming to
preserve the undoubtedly positive results of Einstein’s Theory of
general relativity. The simplest extension is the so called f(R) gravity
which consists in replacing the Ricci scalar R by a function f of it.
We study the effect of electric charge in compact stars assuming that
the charge distribution is proportional to the mass density. We perform a
detailed numerical study of the effect of electric charge using a
polytropic equation of state. We first try to find the numerical results
given in a paper of S. Ray et al. and then apply f(R) gravity to study the
effect of the correction terms given.
Claudia MARASTON (Univ. Portsmouth, UK) INVITED SPEAKER
The formation and evolution of the most massive galaxies in the
Universe: a continuing challenge to Cosmology
Hierarchical galaxy formation in a Lambda-Cold Dark Matter Universe
predicts a bottom-up, environment dependent formation and evolution
of galaxies. The stellar and mass assembly properties of the most
massive galaxies in the Universe present a challenge to this cosmology
which is not yet resolved. I shall review the topic and present new
results using both modelling and observations.
Alessandro MELCHIORRI (Univ. La Sapienza Roma) INVITED
SPEAKER
Cosmic Microwave Anisotropies: current status and perspectives
TBD
Marco MERAFINA (Univ. La Sapienza Roma)
A new point of view in the analysis of equilibrium and dynamical
evolution of globular clusters
Abstract: We develop models of GCs with a different approach by
applying thermodynamic principles to a Boltzmann distribution function,
with an Hamiltonian function which contains an effective potential
depending on the kinetic energy of the stars, due to the effect of tidal
interactions induced by the hosting galaxy. The Hamiltonian function is
solution of the Fokker-Planck equation, solved in a different way with
respect to the King approach. Interesting results implying a different
caloric curve for the analysis of the evolution of GCs
are presented. Effective potential curve, in accordance with the
predicted behaviour, found in N-body simulations of GCs will be
analyzed.
Salvatore MIGNEMI (Univ. Cagliari) INVITED SPEAKER
Physics of Snyder spaces
We review the main properties and applications of Snyder
noncommutative space.
Pierluigi MONACO (Univ. Trieste) INVITED SPEAKER
The construction of cosmological mock galaxy catalogs
The estimation of cosmological parameters and their confidence levels
requires the construction of a large number of galaxy mock catalogs.
The highest requirements are set by the computation of covariance
matrices, that possibly require thousands of realizations. But the
construction of one single mock catalog for the next generation surveys
requires so large simulations that have not been run yet; running
thousands of them with a brute-force N-body approach is out of the
question. I will review the techniques that are presently used for
constructing galaxy mock catalogs, concentrating on those approximate
methods, typically based on Lagrangian Perturbation Theory, that can
be used to generate quick predictions for galaxy clustering and,
possibly, for galaxy lensing. I will then discuss how these techniques
can be used to reproduce deviations from the LambdaCDM model,
starting from the introduction of massive neutrinos.
Riccardo MORICONI (Univ. Federico II Napoli)
Big-bounce cosmology from quantum gravity: the case of cyclical
Bianchi I Universe
We analyse the classical and quantum dynamics of a Bianchi I model in
the presence of a small negative cosmological constant characterizing
its evolution in term of the dust-time dualism. We demonstrate that in a
canonical metric approach, the cosmological singularity is removed in
correspondence to a positive defined value of the dust energy density.
Furthermore, the quantum Big-Bounce is connected to the Universe
turning point via a well-defined semiclassical limit. Then we can reliably
infer that the proposed scenario is compatible with a cyclical Universe
picture. We also show how, when the contribution of the dust energy
density is sufficiently high, the proposedscenario can be extended to the
Bianchi IX cosmology and therefore how it can be regarded as a
paradigm for the generic cosmological model. Finally, we investigate the
origin of the observed cut-off on the cosmological dynamics,
demonstrating how the Big-Bounce evolution can be mimicked by the
same semiclassical scenario, where the negative cosmological constant
is replaced via a polymer discretization of the Universe volume. A direct
proportionality law between such two parameters is then established.
Ugo MOSCHELLA (Univ. Insubria, Italy) INVITED SPEAKER
Soluble two-dimensional models of de Sitter Quantum Field
Theory
We present some new features and unexpected properties concerning
Dirac fields and soluble models of two-dimensional de Sitter QFT
Mohamed Fouad MOURAD
Dirac Equation and Angular Momentum of the Stationary
Axisymmetric Space-Time in the Teleparallel gravity
In the present study, we are interested in finding the spin precession of
a Dirac particle and angular momentum density of the stationary
axisymmetric spacetime in the teleparallel gravity for two different sets
of tetrad fields. For these sets, we obtained the expressions for the
torsion vector, torsion axial-vector and the angular momentum density
in stationary axisymmetric space-time solutions. We found that the
obtained expressions of torsion axial-vector and the angular momentum
density are, in general quite different in both two sets of tetrad fields
while the expressions for the torsion vector have the same value.
Moreover, the vector part connected with Dirac spin has been evaluated
as well. Finally, the special solutions of the stationary axisymmetric
solutions are given.
Shynaray MYRZAKUL (Al-Farahi Kazakh Nat. University)
We discuss the Noether Symmetry Approach in the framework of fessence cosmology showing that the functional form of the R function,
where R is the Ricci scalar, can be determined by the presence of
symmetries. Besides, the method allows to find out exact solutions due
to the reduction of cosmological dynamical system and the presence of
conserved quantities. Some specific cosmological models are worked
out. A cosmological model where a fermion field is non-minimally
coupled with the gravitational field is studied. By applying Noether
symmetry the possible functions for the potential density of the fermion
field and for the coupling are determined. Cosmological solutions
are found showing that the non-minimally coupled fermion field behaves
as an inflaton describing an accelerated inflationary scenario, whereas
the minimally coupled fermion field describes a decelerated period,
behaving as a standard matter field.
Piero NICOLINI (Goether Univ. Frankfurt, Germany) INVITED
SPEAKER
Black hole engineering in short scale modified gravity
We present a possible way to model Planck scale corrections to the
Schwarzschild metric in agreement to recent proposals such as the
quantum N portrait and the self-completeness paradigm. Some
thermodynamics and phenomenology considerations will be also
discussed.
Sergei ODINTSOV (IEEC Univ. Barcelona, Spain) INVITED
SPEAKER
Unified inflation-dark energy universe evolution from new models
of modified gravity.
We review scenarios of unified universe evolution in F(R) gravity,
unimodular F(R) gravity, mimetic F(R) gravity and QG theories.
Number of explicit models and scenarios are presented. The possibility
to avoid future singularities in such modified gravities is discussed.
Non-singular bounce evolutions in such models are considered,
including bounces with consistent dark energy eras. Some attention is
paid also to singular inflation scenario in extended gravity.
Andronikos PALIATHANASIS (Univ. Austral do Chile)
Integrability in modified theories of gravity
The integrability of the gravitational field equations in minisuperspace
approach is studied for the fourth-order theory of gravity f(R) and the
second-order theory f(T). The two approach which are applied are that
of the existence of group invariant transformations and that of movable
singularities.
Paolo PANI (Univ. La Sapienza, Roma/CENTRA-IST Lisbon,
Portugal) INVITED SPEAKER
Probing Dark Matter with Strong Gravity
TBD
Maria Alessandra PAPA (MPG-AEI/Univ. Wisconsin) INVITED
SPEAKER
This is a happy time for gravitational wave (GW) physics. The first
detections of GWs, short duration signals from the merger of binary
black hole systems, have opened a new window on the Universe. As
the detectors' sensitivity improves and as the observation runs span
longer and longer periods we expect new and exciting science. One of
the targets of the GW observational program are weak, long-lasting
signal. The emission mechanism, signal morphology and search
techniques are very different from the ones employed in the transient-
signal searches. I will review the status of the field, concentrate on the
deepest and broadest surveys and for these present the latest results.
Alessandro PAPITTO (INAF-OAR Roma) INVITED SPEAKER
Relativistic broadening of X-ray emission features from accretion
disks in neutron star low-mass X-ray binaries
Low mass X-ray binaries (LMXB) are composed of a compact object (a
neutron star or a black hole) that accretes the mass transferred by a low
mass companion star, via an accretion disk. The spectral modelling of
the emission lines originated by reflection of the accretion driven X-ray
emission off the inner parts of the disk is a fundamental probe of the
dynamics of the accretion flow, a few gravitational radii away from the
compact object. The shape of such emission features is broadened and
skewed by the rotation at relativistic speeds of the disk plasma deep in
the gravitational well of the compact object, and carries information
about the structure and size of the accretion disk. The sensitivity and
spectral resolution capabilities of XMM-Newton have been recently fully
exploited to probe the innermost regions around accreting neutron stars
in LMXBs through the modelling of such reflection features, among
which the Fe K complex stands out. I will review the main results
recently obtained, with a particular focus on accreting millisecond
pulsars, quickly spinning neutron stars that possess a magnetosphere
that is able to truncate the disk flow a few tens of km from the surface.
Roberto PASSANTE (Univ. Palermo) INVITED SPEAKER
Casimir-Polder interaction between two uniformly accelerated
atoms and the Unruh effect
We consider the dispersion (Casimir-Polder) interaction between two
ground-state atoms, interacting with the quantum electromagnetic field
and moving with a uniform acceleration in the vacuum. We separate
vacuum fluctuations and radiation reaction contributions to the
interaction energy, and discuss the relation of our results with the Unruh
effect. We show that the accelerated motion of the atoms significantly
changes the distance-dependence of their interaction energy and that
the interaction exhibits a transition from the Unruh "thermal" shortdistance behavior to a new long-distance non-thermal behavior. Finally,
we argue that Casimir-Polder interactions between accelerating atoms
could be a suitable system to observe the Unruh effect and, in general,
quantum effects related to an accelerated motion.
Giovanni PERES (INAF-OA Palermo) INVITED SPEAKER
From Supernovae to Supernovae Remnants: Bridging the Gap
(Miceli, M., Orlando, S., Peres, G. - authors)
Supernova remnants (SNRs), the remains of supernovae (SN)
explosions, are diffuse, extended, sources with a quite complex
morphology. General consensus is that the morphology reflects the
physical and the chemical properties of both the progenitor SN and of
the surrounding environment. Thus, the study of SNRs may help us to
trace back the structure and the chemical composition of SN ejecta, to
investigate the dynamics and the energetics of SN explosions, and to
unveil the structure of the medium immediately surrounding the
progenitor star.Her we present the first results of a project aimed at
linking the morphological properties of SNRs to the physical properties
of the progenitor SN engine (prescribed as the initial condition)
and to the characteristicsof the environment in which the SN occurs
(prescribed as the boundary conditions). We present high-resolution
three-dimensional hydrodynamic simulations describing the evolution of
SN 1987A and of Cassiopeia A from the immediate aftermath of their
progenitor SN explosions to the current age. In both cases, by
comparing model results with X-ray observations, we have been able to
derive the initial structure of ejecta immediately after the SN explosion
and to derive the energy and mass of initial anisotropies developed
during the initial outburst which are responsible for the current
morphology of the remnants. With this approach we have given
important constraints to current models of SN explosions. Also we have
derived the structure and density distribution of the medium
immediately surrounding the progenitor SN explosions, thus providing
important clues on the final stages of stellar evolution.
Delphine PERRODIN (INAF-OA Cagliari, Italy)
Detecting Gravitational Waves with Pulsars: the LEAP project
A background of nanohertz gravitational waves from supermassive
black hole binaries could soon be detected by pulsar timing arrays,
which measure the times-of-arrival of radio pulses from millisecond
pulsars with very high precision. The European Pulsar Timing Array
uses five large European radio telescopes to monitor high-precision
millisecond pulsars, imposing in this way strong constraints on a
gravitational wave background. To achieve the necessary precision
needed to detect gravitational waves, the Large European Array for
Pulsars (LEAP) performs simultaneous observations of pulsars with all
five telescopes, which allows us to coherently add the radio pulses,
maximize the signal-to-noise of pulsar signals and increase the
precision of times-of-arrival. We report on the progress made and
results obtained by the LEAP collaboration, and in particular on the
addition of the Sardinia Radio Telescope to the LEAP observations. In
addition, we discuss how LEAP can be used to monitor strong-gravity
systems such as double neutron star systems and impose strong
constraints on post-keplerian parameters.
Valeria PETTORINO (Univ. Heidelberg, Germany)
SPEAKER
Dark Energy and Modified Gravity after Planck
INVITED
TBD
Elena PIAN (INAF-IASF Bologna/SNS Pisa) INVITED SPEAKER
Gamma-ray burst supernovae: the most powerful explosions in the
Universe
Long gamma-ray bursts are known to be associated with strippedenvelope core-collapse supernovae with high kinetic energy. A class of
super-luminous core-collapse supernovae has recently surged to
attention and study. These may also be connected with an ultra-long
variety of gamma-ray bursts. I will review the recent observations and
the properties and diversity of these various classes of highly luminous
and energetic phenomena.
Innocenzo Mario PINTO (LIGO-INFN Sannio) INVITED SPEAKER
Thermal Noise in Interferometric Detectors - the LIGO Optimized
Test Mass Coatings
The LIGO noise floor in the intermediate frequency band between a few
tens and a few hundreds Hertz is set by Brownian noise in the highly
reflective test mass coatings. This is also the band where the antenna
noise attains its minimum, and hence determines the instrument
visibility distance. Strategies for reducing coating thermal noise, state of
the art design criteria, and future options for next generation detectors
are discussed.
Guido PIZZELLA (LNF-INFN Frascati) INVITED SPEAKER
Calibration of gravitational wave detectors
TBD
Andrea POSSENTI (INAF-OA Cagliari) INVITED SPEAKER
The intriguing science of the Fast Radio Bursts
The Fast Radio Burst (FRBs) are millisecond duration dispersed
radio transients signals which have now been observed at various
single-dish radio telescopes. Models of the host galaxy and of the
intergalactic medium suggest that they may have cosmological origin.
However, other models have proposed a galactic origin. The talk will
report on the current status of the research about these radio sources,
and will highlight under which conditions the FRBs could be used
for fundamental physics investigations.
Giovanni PRODI (Univ. Trento) INVITED SPEAKER
Overview of Gravitational Wave Observations on behalf of the
LIGO Scientific Collaboration and the Virgo Collaboration
TBD
Fulvio RICCI (Univ. La Sapienza Roma/INFN) INVITED SPEAKER
The Network of the Advanced GW Detectors: Status and Future
Perspectives
We report on the current status of the GW network and the perspectives
of its future evolution
Massimiliano RINALDI (Univ. Trento/TIFPA) INVITED SPEAKER
Dark energy from classical Yang-Mills Higgs fields coupled to
gravity
I will discuss how Einstein gravity minimally coupled to Yang-Mills Higgs
equations can explain the current acceleration of the Universe.
Lucia RIZZUTO (Univ. Palermo) INVITED SPEAKER
Resonance interaction between two identical atoms uniformly
accelerated in vacuum
We investigate the resonance interaction between two uniformly
accelerated identical atoms, one in an excited level and the other in the
ground-state, prepared in a correlated (symmetric or antisymmetric)
state. We suppose the atoms interacting with the scalar or the
electromagnetic field in the vacuum state. Using second-order
perturbation theory, we separate the contributions of vacuum
fluctuations and radiation reaction to the resonance interaction, and
show that the uniform acceleration of the two atoms significantly affects
their interaction. In particular, we show that Unruh "thermal" fluctuations
do not affect the resonance interatomic interaction, which is exclusively
modified by the radiation-reaction correction. We also show that in the
limit of a large interatomic distance, non-thermal effects in the radiation
reaction contribution change qualitatively the distance-dependence of
the resonance interaction.
Piero ROSATI (Univ. Ferrara) INVITED SPEAKER
Dark and luminous matter distribution of CLASH-VLT galaxy
clusters with high-quality lensing and kinematical data
The combination of multi-color HST imaging and extensive
spectroscopy of massive galaxy clusters, from the inner core out to 2-3
viral radii, allow their dark matter and baryonic mass distribution to be
derived independently using strong/weak-lensing techniques and galaxy
dynamics. Specifically, the CLASH-VLT large programme has targeted
12 CLASH clusters (at z=0.2-0.6) spectroscopically identifying 600-1100
galaxy members per cluster, as well as multiply lensed systems.
Additional VLT/MUSE integral-field spectroscopy, in some cases, has
provided a complete view of the central 300-400 kpc, velocity
dispersions of cluster galaxies and secured an unprecedented large
number of multiple images. With this combined data set, we show how
to derive robust mass density profiles over three decades in radius and
to investigate the inner structure of these clusters with high-precision
strong lensing models and kinematical information. We find that the
sub-halo mass function and the inner slope of the dark-matter halos are
difficult to reconcile with LCDM cosmological simulations.
Paolo SALUCCI (SISSA, Trieste) INVITED SPEAKER
Dark Matter Mystery
The issue of dark matter in the Universe, as the time from its discovery
passes on, gets always more complex and even more misterious . To
date we have no hint for DM in LHC p-p annihilations, no particle
detected by underground laboratories. More seriously no Physics
beyond the standard model The cosmological structures as galaxies
and clusters and their time evolution are very different from the
expected ones, if a collisionless cold particle would make the required
missing mass. It is time to rethink to the "dark matter issue" starting, not
from a paradigm, but from the whole observational scenario.
Roberto SCARAMELLA (INAF-OAR Roma, Italy)
Euclid: the next space mission for Cosmology
Euclid is the next ESA mission for Cosmology. It has passed the
Preliminary Design Review and it is expected to be launched in 4 four
years. Euclid will survey most of the extragalactic sky, acquiring data in
optical imaging, near infrared photometry and nir spectra.
Over a lifetime of six years the survey will provide a wealth of
information
for
most
of
the
branches
of
astrophysics.
However, its main aim is to investigate the main actors on the
cosmological scene (e.g. dark stuff and/or extended G.R.?). The goal
will be pursued by measuring via cluttering and gravitational lensing the
time evolution of the expansion and of the growth of structures to an
unparalleled precision. This will be achieved by having both a large
sample (several billions of galaxies) and a strict monitoring and control
of systematic effects.
Paolo SCUDELLARO (Univ. Federico II Napoli) POSTER
TBD
Alighieri SPERELLO DI SEREGO (INAF-OA Arcetri) INVITED
SPEAKER
Cosmic Polarization Rotation: testing the foundations of General
Relativity
TBD
Cosimo STOMAIOLO (INFN Napoli)
I intend to present a new approach to torsion theories
Guglielmo TINO (Univ. Firenze) INVITED SPEAKER
Testing gravity with atomic interferometers and clocks on ground
and in space"
TBD
Gian Paolo VACCA (Univ. La Sapienza/INFN Roma) INVITED
SPEAKER
Asymptotic safety for gravity: status and perspectives
The QFT formulation based on functional renormalisation group
techniques is reviewed together with its application to the study of
gravity as a QFT, fundamental or effective. I will critically discuss some
aspects of this program together with the technical difficulties
encountered so far.
Alberto VECCHIO (Univ. Birmingham, UK) INVITED SPEAKER
Properties of the first observed binary black hole merger
TBD
Daniele VERNIERI (IAP Paris)
Status of Horava gravity: from theory to cosmology
Horava gravity has been proposed as an ultraviolet completion to
General Relativity. Adding to the gravitational action higher-order spatial
derivatives without adding higher-order time derivatives leads to a
modification of the graviton propagator, which renders the theory powercounting renormalizable at the expense of violating Lorentz symmetry at
all scales. Perhaps surprisingly, the theory appears to be
phenomenologically viable in its more general form. I will first talk about
the foundations of the theory and its various restricted versions
proposed so far. Then, I will discuss the cosmology of the low-energy
limit of the theory and place tight constraints on its parameters using
several cosmological data sets.
Stefano VIAGGIU (Univ. Tor Vergata Roma)
Finite size effects at the apparent horizon.
We present our recent proposal for a Modified Bekenstein-Hawking
entropy formula together with its consequence for the cosmology and
for the nature the cosmological constant.
Francesca VIDOTTO (Radboud Univ. Njimegen, NL) INVITED
SPEAKER
Quantum Gravity Phenomenology with Primordial Black Holes
Quantum gravity may allow black holes to decay into white holes. If so,
the lifetime of a black hole would be shorter than the one given by
Hawking evaporation, solving the information paradox. A concrete
calculation can be performed using loop quantum gravity technics,
supporting this picture. Interestingly, this could open to a new window
for quantum-gravity phenomenology, in connection with the existence of
primordial black holes. I discuss in particular the possibility to observe
an astrophysical emission in the radio and in the gamma wavelengths,
and I will briefly overview the ongoing research to understand the
possible consequences of the model for cosmology.
Gaetano VILASI (INFN Nappli/Univ. Salerno) INVITED SPEAKER
TBA
Aneta WOJNAR (Univ. Wroclaw, PL/Univ. Napoli, Italy)
Equilibrium and stability of relativistic stars in extended theories
of gravity"
We study static, spherically symmetric equilibrium configurations in
extended theories of gravity (ETG). We calculate the differential
equations for the stellar structure in such theories in a very generic form
i.e., the Tolman-Oppenheimer-Volkof generalization for any ETG is
introduced. Stability analysis is also investigated with special focus on
the particular example of scalar-tensor gravity.
Michael Florian WONDRAK (FIAS-Univ. Fankfurt, Germany)
Unparticle Effects
TBD