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相关论文: Gravitational entropies in LTB dust models

200 篇论文

We look at a gas of dust and investigate how its entropy evolves with time under a spherically symmetric gravitational collapse. We treat the problem perturbatively and find that the classical thermodynamic entropy does actually increase to…

广义相对论与量子宇宙学 · 物理学 2007-05-23 Morad Amarzguioui , Oyvind Gron

We consider inhomogeneous spherically symmetric models based on the Lema\^{i}tre-Tolman-Bondi (LTB) metric, assuming as its source an interactive mixture of ordinary baryonic matter, cold dark matter and dark energy with a coupling term…

广义相对论与量子宇宙学 · 物理学 2022-07-07 Roberto C. Blanquet-Jaramillo , Roberto A. Sussman , Maximo Aguero , German Izquierdo

We explore a broad class of three-parameter inflationary models, called the $\Lambda$-inflation, and its observational predictions: high abundance of cosmic gravitational waves consistent with the Harrison-Zel'dovich spectrum of primordial…

天体物理学 · 物理学 2016-12-28 V. N. Lukash , E. V. Mikheeva

Models of inflation where the entropic directions have large and negative masses $|m_s| \gg H$ can be well described by a single-field EFT with an imaginary sound speed $c_s$. Among other features, they predict an exponential enhancement of…

宇宙学与河外天体物理 · 物理学 2020-08-19 Ricardo Z. Ferreira

We investigate the cosmological implications of generalized mass-to-horizon entropy, a two-parameter extension of the standard Bekenstein entropy based on the mass-to-horizon relation. Assuming the entropy balance relation, we derive the…

广义相对论与量子宇宙学 · 物理学 2026-05-26 Smeehan S Shameeem , Priyesh K , Krishna P. B , Titus K Mathew

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,…

广义相对论与量子宇宙学 · 物理学 2021-07-27 Hussain Gohar , Vincenzo Salzano

In this article, our goal is to investigate the cosmological dynamics and structure formation in a modified cosmological framework inspired by a generalized mass-to-horizon entropy relation and consistent with the Clausius relation.…

广义相对论与量子宇宙学 · 物理学 2026-04-20 Subhra Mondal , Amitava Choudhuri

We investigate classes of shear-free cosmological dust models with irrotational fluid flows within the framework of $f(T)$ gravity. In particular, we use the $1 + 3$ covariant formalism and present the covariant linearised evolution and…

广义相对论与量子宇宙学 · 物理学 2022-07-27 Heba Sami , Shambel Sahlu , Amare Abebe , Peter K. S. Dunsby

This paper rigorously examines the potential of the $f(T, \mathcal{T})$ theory as a promising framework for understanding the dark sector of the universe, particularly in relation to cosmic acceleration. The $f(T, \mathcal{T})$ theory…

宇宙学与河外天体物理 · 物理学 2025-01-28 M. Koussour , O. Donmez , S. Bekov , A. Syzdykova , S. Muminov , A. I. Ashirova

In this work, two originally separate adjustments for the Friedmann equations are concurrently considered. Firstly, the fractal structure of the black hole horizon region is imposed by the Barrow entropy. The second adjustment is the…

广义相对论与量子宇宙学 · 物理学 2024-06-13 Tuhina Ghorui , Prabir Rudra , Farook Rahaman

Entropic cosmology with the R\'{e}nyi entropy of the apparent horizon $S_R=(1/\alpha)\ln(1+\alpha S_{BH})$, where $S_{BH}$ is the Bekenstein--Hawking entropy, is studied. By virtue of the thermodynamics-gravity correspondence a model of…

综合物理 · 物理学 2026-05-04 S. I. Kruglov

Consistency constraints for low-energy theories, especially those lacking Lorentz invariance, have recently garnered attention. Building on results from black hole thermodynamics, we investigate the conjecture that leading irrelevant…

高能物理 - 理论 · 物理学 2025-08-22 Lucas Fernández-Sarmiento , Riccardo Penco , Rachel A Rosen

A perfect fluid, spatially flat cosmology in a $f(T)$ model, derived from a recently proposed general Born-Infeld type theory of gravity is studied. Four dimensional cosmological solutions are obtained assuming the equation of state…

广义相对论与量子宇宙学 · 物理学 2014-12-04 Soumya Jana

We consider oscillators evolving subject to a periodic driving force that dynamically entangles them, and argue that this gives the linearized evolution around periodic orbits in a general chaotic Hamiltonian dynamical system. We show that…

高能物理 - 理论 · 物理学 2016-02-08 Curtis T. Asplund , David Berenstein

In this study, we investigate the role of bulk viscosity in $f(Q,T)$ gravity in explaining late-time cosmic acceleration. This model, an extension of symmetric teleparallel gravity, introduces viscosity into cosmic matter dynamics for a…

宇宙学与河外天体物理 · 物理学 2024-05-14 M. Koussour , Abdelghani Errehymy , O. Donmez , K. Myrzakulov , M. A. Khan , B. Çil , E. Güdekli

The aim of this work is to study the role of relative entropy in the thermodynamics of black holes and cosmological horizons. We adapt some recent results on the relative entropy of coherent excitations of the vacuum, to find the variation…

广义相对论与量子宇宙学 · 物理学 2023-09-06 Edoardo D'Angelo

This study investigates the cosmological dynamics of an accelerating universe within the framework of teleparallel gravity using an exponential f(T) functional form. To obtain exact cosmological solutions, a hybrid scale factor is employed…

广义相对论与量子宇宙学 · 物理学 2026-05-27 Rajalakshmi Jena , Vishal M C , Sankarsan Tarai

In this thesis, we study a variety of phenomena in strongly coupled quantum field theories by performing calculations in their gravitational duals. We compute entanglement entropy in a variety of holographic systems, paying particular…

高能物理 - 理论 · 物理学 2019-12-23 Ronnie Rodgers

The growing cosmological interest of different entropy functions (like the Tsallis entropy, the R\'{e}nyi entropy, the Barrow entropy, the Sharma-Mittal entropy, the Kaniadakis entropy and the Loop Quantum gravity entropy) naturally raises…

广义相对论与量子宇宙学 · 物理学 2023-09-18 Sergei D. Odintsov , Simone D'Onofrio , Tanmoy Paul

Recently, the R\'{e}nyi and Tsallis generalized entropies have extensively been used in order to study various cosmological and gravitational setups. Here, using a special type of generalized entropy, a generalization of both the R\'{e}nyi…

广义相对论与量子宇宙学 · 物理学 2018-04-05 A. Sayahian Jahromi , S. A. Moosavi , H. Moradpour , J. P. Morais Graça , I. P. Lobo , I. G. Salako , A. Jawad