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Related papers: Gravitational entropies in LTB dust models

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We introduce quasi-local integral scalar variables for the study of spherically symmetric Lemaitre-Tolman-Bondi (LTB) dust models. Besides providing a covariant, and theoretically appealing, interpretation for the parameters of these…

General Relativity and Quantum Cosmology · Physics 2010-02-01 Roberto A Sussman

Barrow proposed that the area law of the horizon entropy might receive a "fractal correction" $S\propto A^{1+\Delta/2}$ due to quantum gravitational effects, with $0\leqslant \Delta \leqslant 1$ measures the deviation from the standard area…

General Relativity and Quantum Cosmology · Physics 2022-12-14 Sofia Di Gennaro , Hao Xu , Yen Chin Ong

We consider the time evolution of two entropy-like quantities, the holographic entanglement entropy and causal holographic information, in a model of holographic thermalization dual to the gravitational collapse of a thin planar shell.…

High Energy Physics - Theory · Physics 2014-09-24 Ville Keranen , Hiromichi Nishimura , Stefan Stricker , Olli Taanila , Aleksi Vuorinen

Various cosmological models in frames of $F(T)$ gravity are considered. The general scheme of constructing effective dark energy models with various evolution is presented. It is showed that these models in principle are compatible with…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Artyom V. Astashenok

Several models of level densities exist and they often make simplified assumptions regarding the overall behavior of the total level densities (LD) and the intrinsic spin and parity distributions of the excited states. Normally, such LD…

Nuclear Theory · Physics 2021-06-02 G. P. A. Nobre , D. A. Brown , M. W. Herman

Recently, Bousso and Penington (BP) made a proposal for the entanglement wedge associated to a gravitating bulk region. In this paper, we derive this proposal in time-reflection symmetric settings using the gravitational path integral. To…

High Energy Physics - Theory · Physics 2025-08-27 Sami Kaya , Pratik Rath , Kyle Ritchie

In this work, I present for the first time the analysis concerning the growth of matter fluctuations in the framework of $f(R,T)$ modified gravity where I presume $f(R,T) = R + \lambda T$, where $R$ denote the Ricci scalar, $T$ the trace of…

General Relativity and Quantum Cosmology · Physics 2020-11-06 Snehasish Bhattacharjee

We focus on viable $f(T)$ teleparallel cosmological models, namely power law, exponential and square-root exponential, carrying out a detailed study of their evolution at all scales. Indeed, these models were extensively analysed in the…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-10 Micol Benetti , Salvatore Capozziello , Gaetano Lambiase

Based on the Lewkowycz-Maldacena prescription and the fine structure analysis of holographic entanglement proposed in arXiv:1803.05552, we explicitly calculate the holographic entanglement entropy for warped CFT that duals to AdS$_3$ with a…

High Energy Physics - Theory · Physics 2019-02-20 Qiang Wen

This study explores the interaction between non-extensive entropic FLRW cosmology and the power-law inflationary model, with a focus on the overlap between the scalar spectral index `$n_s$' and the tensor-to-scalar ratio `$r$'. Based on a…

General Relativity and Quantum Cosmology · Physics 2024-09-26 A. Khodam-Mohammadi

While the Bekenstein-Hawking entropy is the unique notion of entropy that makes classical black hole thermodynamics consistent, alternative entropy notions (R\'enyi, Tsallis, and generalized constructs) abound in the literature. We explore…

General Relativity and Quantum Cosmology · Physics 2022-12-07 Shin'ichi Nojiri , Sergei D. Odintsov , Valerio Faraoni

We present a systematic exploration of dark energy and modified gravity models containing a single scalar field non-minimally coupled to the metric. Even though the parameter space is large, by exploiting an effective field theory (EFT)…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-03 Louis Perenon , Federico Piazza , Christian Marinoni , Lam Hui

Generalised Teleparallel gravity, also referred to as f(T) gravity, has been recently proposed as an extended theory of gravitation able to give rise to an accelerated expansion in a matter only universe. The cosmic speed up is driven by an…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Vincenzo F. Cardone , Ninfa Radicella , Stefano Camera

We examine the exact perturbations that arise from the q-average formalism that was applied in the preceding article (part I) to Lemaitre-Tolman-Bondi (LTB) models. By introducing an initial value parametrization, we show that all LTB…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Roberto A. Sussman

The accelerated expansion of the universe remains one of the most profound puzzles in modern cosmology, often attributed to dark energy within the framework of General Relativity. As an alternative, modified teleparallel gravity theories…

General Relativity and Quantum Cosmology · Physics 2025-12-23 K. S. Kavya , T. Vinutha , B. Revathi

We investigate the joint density-velocity evolution in $f(R)$ gravity using smooth, compensated spherical top-hats as a proxy for the non-linear regime. Using the Hu-Sawicki model as a working example, we solve the coupled continuity, Euler…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-24 Sharvari Nadkarni-Ghosh , Sandip Chowdhury

Modified cosmology based on Barrow entropy arises from the gravity-thermodynamics conjecture, in which the standard Bekenstein-Hawking entropy is replaced by the Barrow entropy of quantum-gravitational origin, characterized by the Barrow…

General Relativity and Quantum Cosmology · Physics 2025-09-08 Giuseppe Gaetano Luciano , Andronikos Paliathanasis , Emmanuel N. Saridakis

In this work, we consider four $f(R)$ gravity models -- the Hu-Sawicki, Starobinsky, Exponential and Tsujikawa models -- and use a range of cosmological data, together with Markov Chain Monte Carlo sampling techniques, to constrain the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-05 Christine R. Farrugia , Joseph Sultana , Jurgen Mifsud

When the Bekenstein-Hawking entropy is modified, ambiguity often arises concerning whether the Hawking temperature or the thermodynamic mass should be modified. The common practice, however, is to keep the black hole solution the same as…

General Relativity and Quantum Cosmology · Physics 2025-01-20 Hengxin Lu , Sofia Di Gennaro , Yen Chin Ong

We consider the ideal Fermi gas of indistinguishable particles without spin but with electric charge, confined to a Euclidean plane $\mathbb R^2$ perpendicular to an external constant magnetic field of strength $B>0$. We assume this…

Mathematical Physics · Physics 2023-03-01 Hajo Leschke , Alexander V. Sobolev , Wolfgang Spitzer
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