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Related papers: Lemaitre-Tolman-Bondi Static Universe in Rastall-l…

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We investigate stability of the Einstein static solution against homogeneous scalar, vector and tensor perturbations in the context of Rastall theory of gravity. We show that this solution in the presence of perfect fluid and vacuum energy…

General Relativity and Quantum Cosmology · Physics 2018-07-10 F. Darabi , K. Atazadeh , Y. Heydarzade

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

We analyze the stability of the Einstein static universe by considering homogeneous scalar perturbations in the context of f(R) modified theories of gravity. By considering specific forms of f(R), the stability regions of the solutions are…

General Relativity and Quantum Cosmology · Physics 2012-06-22 Christian G. Boehmer , Lukas Hollenstein , Francisco S. N. Lobo

We analyze inhomogeneous cosmological models in the local Universe, described by the Lema\^itre-Tolman-Bondi (LTB) metric and developed using linear perturbation theory on a homogeneous and isotropic Universe background. Focusing on the…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Tiziano Schiavone , Giovanni Montani

Hybrid metric-Palatini gravity is a recent and novel approach to modified theories of gravity, which consists of adding to the metric Einstein-Hilbert Lagrangian an f(R) term constructed a la Palatini. It was shown that the theory passes…

General Relativity and Quantum Cosmology · Physics 2015-02-19 Christian G. Boehmer , Francisco S. N. Lobo , Nicola Tamanini

We derive a class of non-static inhomogeneous dust solutions in f(R) gravity described by the Lemaitre-Tolman-Bondi (LTB) metric. The field equations are fully integrated for all parameter subcases and compared with analogous subcases of…

General Relativity and Quantum Cosmology · Physics 2017-11-28 Roberto A Sussman , Luisa G Jaime

We present a brief overview of the stability analysis of the Einstein static universe in various modified theories of gravity, like f(R) gravity, Gauss-Bonnet or f(G) gravity, and Horava-Lifshitz gravity.

General Relativity and Quantum Cosmology · Physics 2016-11-15 Christian G. Boehmer , Lukas Hollenstein , Francisco S. N. Lobo , Sanjeev S. Seahra

We focus on weak inhomogeneous models of the Universe at low redshifts, described by the Lema\^itre-Tolman-Bondi (LTB) metric. The principal aim of this work is to compare the evolution of inhomogeneous perturbations in the $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-20 Tiziano Schiavone , Giovanni Montani

The Rastall gravity is a modification of Einstein's general relativity, in which the energy-momentum conservation is not satisfied and depends on the gradient of the Ricci curvature. It is in dispute whether the Rastall gravity is…

Astrophysics of Galaxies · Physics 2020-08-26 Meirong Tang , Zhaoyi Xu , Jiancheng Wang

The purpose of this paper is to analyze the existence of static stable Einstein universe using inhomogeneous linear perturbations in the context of $f(R,T)$ gravity ($R$ and $T$ denote the scalar curvature and trace of the stress-energy…

General Relativity and Quantum Cosmology · Physics 2020-02-19 M. Sharif , Arfa Waseem

The Einstein static (ES) state is a good candidate for describing the very early universe in terms of a regular cosmological model in which the Big Bang singularity is avoided. In the present study we propose an ES solution in the framework…

General Relativity and Quantum Cosmology · Physics 2022-08-18 Hamid Shabani , Amir Hadi Ziaie , Hooman Moradpour

We study the stability of static, spherically symmetric solutions of Rastall's theory in the presence of a scalar field with respect to spherically symmetric perturbations. It is shown that the stability analysis is inconsistent in the…

General Relativity and Quantum Cosmology · Physics 2021-02-24 K. A. Bronnikov , Júlio C. Fabris , Oliver F. Piattella , Denis C. Rodrigues , Edison C. O. Santos

We analyze the stability of the Einstein static universe by considering homogeneous perturbations in the context of f(G) modified Gauss-Bonnet theories of gravity. By considering a generic form of f(G), the stability region of the Einstein…

General Relativity and Quantum Cosmology · Physics 2009-03-30 Christian G. Boehmer , Francisco S. N. Lobo

Loop Quantum Cosmology strongly modifies the high-energy dynamics of Friedman-Robertson-Walker models and removes the big-bang singularity. We investigate how LQC corrections affect the stability properties of the Einstein static universe.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Luca Parisi , Marco Bruni , Roy Maartens , Kevin Vandersloot

The stability of the Einstein static universe against the homogeneous scalar perturbations in $f(T)$ gravity is analyzed. Both the spatial closed and open universes are considered. We find that the stable Einstein static solutions exist in…

General Relativity and Quantum Cosmology · Physics 2011-10-05 Puxun Wu , Hongwei Yu

By rescaling the Gauss-Bonnet (GB) coupling constant $\alpha \rightarrow \alpha/(D-4)$ and considering the $D \rightarrow 4$ limit, the GB gravity gives rise to nontrivial modification of general relativity in four dimensions. In this work,…

General Relativity and Quantum Cosmology · Physics 2020-04-14 Shou-Long Li , Puxun Wu , Hongwei Yu

In this paper we explore the possibility to find exact solutions for Teleparallel Gravity (TG) of the type of spherically symmetric Lema\^\i tre-Tolman-Bondi (LTB) dust models. We apply to the LTB metric the formalism of Teleparallel…

General Relativity and Quantum Cosmology · Physics 2022-03-28 Sebastián Nájera , Aram Aguilar , Geovanny A. Rave-Franco , Celia Escamilla-Rivera , Roberto A. Sussman

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

In this study, we explore the thermodynamic aspects of a modified version of Rastall's gravity theory and its implications for cosmological scenarios. We analyze the role of non-conserved energy-momentum tensor equations and investigate…

General Relativity and Quantum Cosmology · Physics 2025-12-01 José A. C. Nogales , K. Luz-Burgoa , Laysa G. Martins

This paper explores stability of the Einstein universe against linear homogeneous perturbations in the background of $f(\mathcal{G},T)$ gravity. We construct static as well as perturbed field equations and investigate stability regions for…

General Relativity and Quantum Cosmology · Physics 2017-07-26 M. Sharif , Ayesha Ikram
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