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Related papers: Gravitational Entropy in Szekeres Class I Models

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We perform a study on quantum entropy production, different kinds of correlations, and their interplay in the driven Caldeira-Leggett model of quantum Brownian motion. The model, taken with a large but finite number of bath modes, is…

Quantum Physics · Physics 2021-11-24 Alessandra Colla , Heinz-Peter Breuer

Tensor-scalar theories of gravitation are commonly employed as extensions of General Relativity that allow to describe a much wider phenomenology. They are also naturally generated as low energy limit of higher-dimensional or unified…

General Physics · Physics 2025-12-09 F. Minotti , G. Modanese

In this review articel we study the gaugings of extended supergravity theories in various space-time dimensions. These theories describe the low-energy limit of non-trivial string compactifications. For each theory under consideration we…

High Energy Physics - Theory · Physics 2008-11-26 Martin Weidner

We study the effects and implications of anisotropies at the scale of galaxy clusters by building an exact general relativistic model of a cluster using the inhomogeneous and anisotropic Szekeres metric. The model is built from a modified…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 M. A. Troxel , Austin Peel , Mustapha Ishak

Earlier it was shown that the entropy of an ideal gas, contained in a box and moving in a gravitational field, develops an area dependence when it approaches the horizon of a static, spherically symmetric spacetime. Here we extend the above…

General Relativity and Quantum Cosmology · Physics 2017-10-25 Sourav Bhattacharya , Sumanta Chakraborty , T. Padmanabhan

We present a new approach to solve the 2+1 Teukolsky equation for gravitational perturbations of a Kerr black hole. Our approach relies on a new horizon penetrating, hyperboloidal foliation of Kerr spacetime and spatial compactification. In…

General Relativity and Quantum Cosmology · Physics 2014-11-26 Enno Harms , Sebastiano Bernuzzi , Alessandro Nagar , Anil Zenginoglu

Classical entropy regularization is poorly suited to continuous-time martingale transport, since relative entropy between diffusion laws typically forces their volatility characteristics to coincide. We introduce a specific-entropy…

Probability · Mathematics 2026-05-22 Francois Buet-Golfouse , Anaïs Després , Zhenjie Ren , Xin Zhang

We consider the structure and physical properties of specific classes of neutron, quark, and Bose-Einstein Condensate stars in the conformally invariant Weyl geometric gravity theory. The basic theory is derived from the simplest…

General Relativity and Quantum Cosmology · Physics 2023-04-12 Zahra Haghani , Tiberiu Harko

We investigate entropic force cosmological models with the possibility of matter creation and energy exchange between the bulk and the horizon of a homogeneous and an isotropic flat Universe. We consider three different kinds of entropy,…

General Relativity and Quantum Cosmology · Physics 2021-07-27 Hussain Gohar , Vincenzo Salzano

This work analyzes different notions of entropy and its production in $ep$ and heavy-ion collisions, focusing on the early stages of the collision. To this end, the importance of phenomena such as quantum entanglement and decoherence in…

High Energy Physics - Phenomenology · Physics 2025-02-04 G. S. Ramos

All spacetimes for an irrotational collisionless fluid with a purely electric Weyl tensor, with spacetime curvature determined by the exact Einstein field equations, are shown to be integrable. These solutions include the relativistic…

Astrophysics · Physics 2009-10-22 W. M. Lesame , P. K. S. Dunsby , G. F. R. Ellis

A new solution for the endpoint of gravitational collapse is proposed. By extending the concept of Bose-Einstein condensation to gravitational systems, a cold, compact object with an interior de Sitter condensate phase and an exterior…

General Relativity and Quantum Cosmology · Physics 2023-02-16 Pawel O. Mazur , Emil Mottola

We propose a covariant entropy bound in gravitational theories beyond general relativity (GR), using Wald-Jacobson-Myers entropy instead of Bekenstein-Hawking entropy. We first extend the proof of the bound known in 4-dimensional GR to…

High Energy Physics - Theory · Physics 2021-01-13 Taisuke Matsuda , Shinji Mukohyama

The spontaneous violation of Lorentz and diffeomorphism invariance in a phase near the big bang lowers the entropy, allowing for an arrow of time and the second law of thermodynamics. The spontaneous symmetry breaking leads to…

General Relativity and Quantum Cosmology · Physics 2016-03-08 J. W. Moffat

In this paper we show that the existence of a primarily discrete space-time may be a fruitful assumption from which we may develop a new approach of statistical thermodynamics in pre-relativistic conditions. The discreetness of space-time…

Quantum Physics · Physics 2010-05-17 J. P. Badiali

We study a gravity model in 2+1 dimensions, arising from a generalized Chern-Simons (CS) density we call a Higgs-Chern-Simons (HCS) density. This generalizes the construction of gravitational systems resulting from non-Abelian CS densities…

General Relativity and Quantum Cosmology · Physics 2018-08-08 Eugen Radu , D. H. Tchrakian

A derivation of entropy from the expressions for two dimensional gravitation anomalies is given. Starting from the near horizon anomalous energy-momentum tensors corresponding to particular anomalies, the Virasoro algebra with central…

General Relativity and Quantum Cosmology · Physics 2013-01-29 Bibhas Ranjan Majhi

We systematically extend the statement that the configurational entropy provides an alternative approach to studying gravitational stability of compact objects, carried out in the previous work of M. Gleiser and N. Jiang, Phys. Rev. D {\bf…

General Relativity and Quantum Cosmology · Physics 2023-03-20 P. S. Koliogiannis , G. A. Tsalis , C. P. Panos , Ch. C. Moustakidis

We derive the most general mimetic scalar-tensor theory assuming a healthy "seed" action and accounting for the constraints on the speed of gravitational-wave propagation arising from the GW170817 event. By analysing linear perturbations…

General Relativity and Quantum Cosmology · Physics 2019-02-13 Alexander Ganz , Nicola Bartolo , Purnendu Karmakar , Sabino Matarrese

We give a notion of entropy for general gemetric structures, which generalizes well-known notions of topological entropy of vector fields and geometric entropy of foliations, and which can also be applied to singular objects, e.g. singular…

Differential Geometry · Mathematics 2011-09-27 Nguyen Tien Zung