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Related papers: Thermodynamic stability in an Einstein universe

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This paper analyzes the stability of the closed Einstein static universe by using linear homogeneous perturbations in the framework of energy-momentum squared gravity. This newly developed proposal resolves the primordial singularity and…

General Relativity and Quantum Cosmology · Physics 2021-08-25 M. Sharif , M. Zeeshan Gul

A well-known difficulty of perturbative approaches to quantum field theory at finite temperature is the necessity to address theoretical constraints that are not present in the vacuum theory. In this work, we use lattice simulations of…

High Energy Physics - Phenomenology · Physics 2024-08-30 Peter Lowdon , Owe Philipsen

Establishing a description for confinement is not something simple. In order to try to understand a little about this phenomenon, we will explore the thermodynamics of models that try to describe it in terms of propagators with violation of…

High Energy Physics - Theory · Physics 2018-04-27 A. V. Silva , B. W. Mintz

We analyse in detail the thermodynamics in the canonical and grand canonical ensembles of a class of non-asymptotically flat black holes of the Einstein-(anti) Maxwell-(anti) Dilaton theory in 4D with spherical symmetry. We present the…

General Relativity and Quantum Cosmology · Physics 2013-04-09 Manuel E. Rodrigues , Glauber Tadaiesky Marques

This paper investigates the existence and stability of Einstein universe in the context of $f(R,T,Q)$ gravity, where $Q=R_{\mu\nu}T^{\mu\nu}$. Considering linear homogeneous perturbations around scale factor and energy density, we formulate…

General Relativity and Quantum Cosmology · Physics 2018-12-19 M. Sharif , Arfa Waseem

Thermal fluctuations for a massive scalar field in the Rindler wedge are obtained by applying the point-splitting procedure to the zero temperature Feynman propagator in a conical spacetime. Renormalization is implemented by removing the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 R. Medina , E. S. Moreira , jr

We discuss Einstein-Klein-Gordon system in an environment of an infinite number of scalar fields leading to an external thermal noise. In the lowest order of metric and field perturbations the quadratic fluctuations consist of a sum of…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Z. Haba

We investigate whether or not an Einstein Static universe is a solution to the cosmological equations in $f(R)$ gravity. It is found that only one class of $f(R)$ theories admits an Einstein Static model, and that this class is neutrally…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Rituparno Goswami , Naureen Goheer , Peter K. S. Dunsby

We study the stationary states of a quantum mechanical system describing an atom coupled to black-body radiation at positive temperature. The stationary states of the non-interacting system are given by product states, where the particle is…

Mathematical Physics · Physics 2009-11-10 Jürg Fröhlich , Marco Merkli , Israel Michael Sigal

Thermodynamical Behaviour of Inhomogeneous Universe with Varying $ \Lambda $ in Presence of Electromagnetic Field is obtained. $ F_{12} $ is the non-vanishing component of electromagnetic field tensor. To get a deterministic solution, it is…

General Relativity and Quantum Cosmology · Physics 2010-04-22 Anil Kumar Yadav

We assume the validity of the Bekenstein-Hawking entropy, as given in terms of the horizon area of the Bardeen regular black hole, and consider it as the fundamental thermodynamic equation. We derive and investigate the behavior of the main…

General Relativity and Quantum Cosmology · Physics 2025-02-10 H. Quevedo , M. N. Quevedo , A. Sanchez

We develop a thermal description for photon modes within the context of bouncing universe. Within this study, we start with a Lorentz-breaking dispersion relation which accounts for modified Friedmann equations with a bounce solution. We…

High Energy Physics - Theory · Physics 2022-01-27 A. A. Araújo Filho , A. Yu. Petrov

The features of the fundamental thermodynamical relation (expressing entropy as function of state variables) that arise from the self-gravitating character of a system are analyzed. The models studied include not only a spherically…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Erik A. Martinez

We study the dynamics of perturbations around nonthermal fixed points associated to universal scaling phenomena in quantum many-body systems far from equilibrium. For an N-component scalar quantum field theory in 3+1 space-time dimensions,…

High Energy Physics - Phenomenology · Physics 2023-01-23 Thimo Preis , Michal P. Heller , Jürgen Berges

According to maximum entropy principle, it has been proved that the gravitational field equations could be derived by the extrema of total entropy for perfect fluid, which implies that thermodynamic relations contain information of gravity.…

General Relativity and Quantum Cosmology · Physics 2018-01-17 Xiongjun Fang , Xiaokai He , Jiliang Jing

We study the back-reaction effects of the finite-temperature scalar field and the photon field in the background of an Einstein universe. In each case we find a relation between the temperature of the universe and its radius. These…

General Relativity and Quantum Cosmology · Physics 2009-11-07 M. B. Altaie

We construct a new class of charged rotating solutions of $(n+1)$-dimensional Einstein-Born-Infeld gravity with cylindrical or toroidal horizons in the presence of cosmological constant and investigate their properties. These solutions are…

High Energy Physics - Theory · Physics 2008-11-26 M. H. Dehghani , H. R. Rastegar Sedehi

We discuss Einstein gravity for a fluid consisting of particles interacting with an unidentified environment of some other particles whose dissipative effect is approximated by a diffusion. The environment is described by a time dependent…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Z. Haba

The thermodynamic interpretation of the Stephani Universes is studied in detail. The general expression of the speed of sound and of the thermodynamic schemes associated with a thermodynamic solution is obtained. The constraints imposed on…

General Relativity and Quantum Cosmology · Physics 2024-09-04 Salvador Mengual , Joan Josep Ferrando , Juan Antonio Sáez

The frozen star is a recent proposal for a non-singular solution of Einstein's equations that describes an ultracompact object which closely resembles a black hole from an external perspective. The frozen star is also meant to be an…

General Relativity and Quantum Cosmology · Physics 2023-10-19 Ram Brustein , A. J. M. Medved , Tamar Simhon