368 citations · 2.3k across the 134 of their papers we have counts for
28 papers · 1 filter
On more general Gibbons-Hawking-York boundary terms for f(R) gravity
Federico Scali, Sergio Luigi Cacciatori, Matteo Galaverni +1
More general boundary conditions are introduced - with respect to known literature - which produce a well-posed stationary action principle in gravity. These conditions enco…
Black Holes, Gravitational Waves and Space-Time Singularities Lemaitre Conference 2024
Massimo Bianchi, Sergio Luigi Cacciatori, Matteo Galaverni +2
This editorial introduces the topical collection arising from the Lemaitre Conference 2024 - the second in a series of meetings dedicated to the scientific legacy of Georges Lemait…
Local observers in stationary axisymmetric dust spacetimes
Matteo Fontana, Sergio Luigi Cacciatori, Roberto Peron
In this work, we construct a locally inertial reference system adapted to a geodesic observer in stationary, axisymmetric dust solutions of the Einstein equations employed as effec…
Minimum spacetime length and the thermodynamics of spacetime
Valeria Rossi, Sergio Luigi Cacciatori, Alessandro Pesci
Theories of emergent gravity have established a deep connection between entropy and the geometry of spacetime by looking at the latter through a thermodynamic lens. In this framewo…
Asymptotically Conically Minkowskian spacetimes from self-gravitating dust
Matteo Fontana, Federico Scali, Sergio Luigi Cacciatori
In this work we investigate some non-Newtonian effects in exact solutions of the Einstein equations, which describe stationary and axisymmetric configurations of self-gravitating d…
Dark Energy
Sergio Luigi Cacciatori, Vittorio Gorini, Federico Re
Among the great mysteries that physics has not yet solved are undoubtedly those of dark energy and dark matter. In this chapter we deal with the first of them. We will expound in d…
Dark Matter
Sergio Luigi Cacciatori, Vittorio Gorini, Federico Re
In this article we address the mystery of dark matter. We expound the various evidences, astrophysical and cosmological, leading to hypothesize the existence of an invisible form o…
Non canonical polarizations of Gravitational Waves
Stefano Bondani, Sergio Luigi Cacciatori
We hereby propose an alternative and additional angle on the nature of gravitational waves (GWs), postulating the theoretical and experimental possibility that GWs carry a deformat…
Equatorial Lensing in the Balasin-Grumiller Galaxy Model
Marco Galoppo, Sergio Luigi Cacciatori, Vittorio Gorini +1
The Balasin-Grumiller model has been the first model employed as an attempt towards providing a fully general relativistic description of the dynamics of a disc galaxy. In this pap…
Towards a full general relativistic approach to galaxies
Davide Astesiano, Sergio L. Cacciatori, Federico Re
We analyze the dynamics of a single spiral galaxy from a general relativistic viewpoint. We employ the known family of stationary axially-symmetric solutions to Einstein gravity co…
On Generalized Lemaitre-Tolman-Bondi Metric. Fractal Matter at the end of Matter-Antimatter Recombination
Sergio Cacciatori, Alessio Marrani, Federico Re
Many recent researches have investigated the deviations from the Friedmannian cosmological model, as well as their consequences on unexplained cosmological phenomena, such as dark…
Gravitational waves, 100 years later
Sergio L. Cacciatori
We present a short communication on the recent direct measurements of gravitational waves, made possible by the joint efforts of the LIGO and the Virgo projects. These notes are de…
Analogue Hawking Effect: BEC and Surface Waves
F. Belgiorno, S. L. Cacciatori, A. Farahat +1
We take into account two further physical models which play an utmost importance in the framework of Analogue Gravity. We first consider Bose--Einstein condensates (BEC) and then s…
Analogue Hawking Effect: a master equation
F. Belgiorno, S. L. Cacciatori, A. Viganò
We consider further on the problem of the analogue Hawking radiation. We propose a fourth order ordinary differential equation, which allows to discuss the problem of Hawking radia…
Stimulated emission and Hawking radiation in black hole analogues
F. Belgiorno, S. L. Cacciatori
Stimulated emission by black holes is discussed in light of the analogue gravity program. We first consider initial quantum states containing a definite number of particles, and th…
Tunneling method for Hawking radiation in the Nariai case
F. Belgiorno, S. L. Cacciatori, F. Dalla Piazza
We revisit the tunneling picture for the Hawking effect in light of the charged Nariai manifold, because this general relativistic solution, which displays two horizons, provides t…
Tunneling approach and thermality in dispersive models of analogue gravity
F. Belgiorno, S. L. Cacciatori, F. Dalla Piazza
We set up a tunneling approach to the analogue Hawking effect in the case of models of analogue gravity which are affected by dispersive effects. An effective Schroedinger-like equ…
The Hawking effect in dielectric media and the Hopfield model
F. Belgiorno, S. L. Cacciatori, F. Dalla Piazza
We consider the so-called Hopfield model for the electromagnetic field in a dielectric dispersive medium in a framework in which one allows a space-time dependence of microscopic p…
Experimental quantum cosmology in time-dependent optical media
N. Westerberg, S. Cacciatori, F. Belgiorno +2
It is possible to construct artificial spacetime geometries for light by using intense laser pulses that modify the spatiotemporal properties of an optical medium. Here we theoreti…
Hawking radiation from ultrashort laser pulse filaments
F. Belgiorno, S. L. Cacciatori, M. Clerici +6
Event horizons of astrophysical black holes and gravitational analogues have been predicted to excite the quantum vacuum and give rise to the emission of quanta, known as Hawking r…
Dark matter effects in vacuum spacetime
Luca Rizzi, Sergio Cacciatori, Vittorio Gorini +2
We analyze a toy model describing an empty spacetime in which the motion of a test mass (and the trajectories of photons) evidence the presence of a continuous and homogeneous dist…
Quantum instability for charged scalar particles on charged Nariai and ultracold black hole manifolds
F. Belgiorno, S. L. Cacciatori, F. Dalla Piazza
We analyze in detail the quantum instability which characterizes charged scalar field on three special de Sitter charged black hole backgrounds. In particular, we compute exactly t…
Conserved quantities for the Sitter particles
Sergio L. Cacciatori
Recent observations of the luminosity-red shift relation of distant type Ia supernovae established the fact that the expansion of the universe is accelerated. This is interpreted b…
Pair-production of charged Dirac particles on charged Nariai and ultracold black hole manifolds
F. Belgiorno, S. L. Cacciatori, F. Dalla Piazza
Spontaneous loss of charge by charged black holes by means of pair-creation of charged Dirac particles is considered. We provide three examples of exact calculations for the sponta…