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Related papers: Study of Gravastars in Rastall Gravity

200 papers

In this work we study some aspects of the Rastall gravity, being the thermodynamics consistency of the model the core of this paper, for this purpose we will consider the dynamical equations of Rastall model in a flat FLRW geometry. Under a…

General Relativity and Quantum Cosmology · Physics 2019-10-22 Miguel Cruz , Samuel Lepe , Gerardo Morales-Navarrete

This study explores the application of complexity factor within the context of Rastall gravity, exploring its implications on a static spacetime admitting spherical symmetry associated with anisotropic fluids under an electromagnetic field.…

General Relativity and Quantum Cosmology · Physics 2025-08-20 Tayyab Naseer

Reissner--Nordstr\"om black holes have two static regions: $r > \ro$ and $0 < r < \ri$, where $\ri$ and $\ro$ are the inner and outer horizon radii. The stability of the exterior static region has been established long time ago. In this…

General Relativity and Quantum Cosmology · Physics 2011-03-28 Gustavo Dotti , Reinaldo J. Gleiser

We show that a generic relativistic membrane with in-plane pressure and surface density having the same sign is unstable with respect to a series of warping mode instabilities with high wave numbers. We also examine the criteria of…

General Relativity and Quantum Cosmology · Physics 2023-01-18 Huan Yang , Beatrice Bonga , Zhen Pan

Mazharimousavi and Halilsoy [1] recently proposed wormhole solutions in $f(R)$-gravity that satisfy energy conditions but are unstable. We show here that stability could still be achieved for thin-shell wormholes obtained by gluing the…

General Relativity and Quantum Cosmology · Physics 2019-02-20 Alina Khaybullina , Gulira Tuleganova

In this work, we investigate static configurations of dark energy stars within the framework of Rastall-Rainbow (R-R) gravity, which combines an energy-dependent deformation of spacetime with a nonminimal coupling between matter and…

General Relativity and Quantum Cosmology · Physics 2025-10-21 Ayan Banerjee , Bobur Turimov , Sulton Usanov , Murodbek Vapaev , Yunus Turaev , Zebo Avezmuratova

Various types of inhomogeneous collapse models in general relativity (GR) lead to the formation of spacetime singularities either visible or hidden by a spacetime horizon. Our aim in the present work is to search for nonsingular models in…

General Relativity and Quantum Cosmology · Physics 2025-07-04 Akbar Jahan , Halime Miraghaei , Shayesteh Ghaffari , Amir Hadi Ziaie

In this work, we analyze the observational properties of thin-shell gravastars under two astrophysical frameworks, namely surrounded by optically-thin accretion disks and orbited by hot-spots. We consider the thin-shell gravastar model with…

General Relativity and Quantum Cosmology · Physics 2024-04-02 João Luís Rosa , Daniela S. J. Cordeiro , Caio F. B. Macedo , Francisco S. N. Lobo

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 ergoregion instability is known to affect very compact objects that rotate very rapidly and do not possess a horizon. We present here a detailed analysis on the relevance of the ergoregion instability for the viability of gravastars.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Cecilia B. M. H. Chirenti , Luciano Rezzolla

Using graphs plotted from the Mathematica notebooks posted with our paper ``Dynamical Gravastars'', we show that a dynamical gravastar has no hard surface, and that a second light sphere resides in the deep interior where there is maximum…

General Relativity and Quantum Cosmology · Physics 2024-02-13 Stephen L. Adler

We study spherically symmetric static spacetimes generally filled with an anisotropic fluid in the nonrelativistic general covariant theory of gravity. In particular, we find that the vacuum solutions are not unique, and can be expressed in…

High Energy Physics - Theory · Physics 2011-01-27 Jared Greenwald , V. H. Satheeshkumar , Anzhong Wang

This work investigates some feasible regions for the existence of traversable wormhole geometries in $f(R,G)$ gravity, where $R$ and $G$ represent the Ricci scalar and the Gauss-Bonnet invariant respectively. Three different matter contents…

General Physics · Physics 2018-11-12 M. Farasat Shamir , Saeeda Zia

We consider a way to avoid black hole singularities by gluing a black hole exterior to an interior with a tube-like geometry consisting of a direct product of two-dimensional AdS, dS, or Rindler spacetime with a two-sphere of constant…

General Relativity and Quantum Cosmology · Physics 2009-11-11 O. B. Zaslavskii

A new final state of gravitational collapse is proposed. By extending the concept of Bose-Einstein condensation to gravitational systems, a cold, dark, compact object with an interior de Sitter condensate $p_{_V} = -\rho_{_V}$ and an…

General Relativity and Quantum Cosmology · Physics 2009-10-19 Pawel O. Mazur , Emil Mottola

This research paper presents a black hole solution with a rational non-linear electrodynamics source in the Rastall gravity framework. The paper analyzes the thermodynamic properties of the solution in normal phase space and explores its…

General Relativity and Quantum Cosmology · Physics 2024-03-11 Yassine Sekhmani , Dhruba Jyoti Gogoi , Ratbay Myrzakulov , Javlon Rayimbaev

Millisecond pulsars are perfect laboratories to test possible matter-geometry coupling and its physical implications in light of recent Neutron Star Interior Composition Explorer (NICER) observations. We apply Rastall field equations of…

High Energy Astrophysical Phenomena · Physics 2022-11-22 Waleed El Hanafy

The Weak Gravity Conjecture predicts that in quantum gravity there should exist overcharged states, that is states with charge larger than their mass. Extending this to large masses and charges, we are expecting similar overcharged…

High Energy Physics - Theory · Physics 2023-05-16 Alex Kehagias , Kostas D. Kokkotas , Antonio Riotto , John Taskas , George Tringas

In the present work, we seek for static spherically symmetric solutions representing wormhole configurations in generalized Rastall gravity (GRG). In this theory, a varying coupling parameter could act as dark energy (DE) and thus, it can…

General Relativity and Quantum Cosmology · Physics 2025-04-08 Naser Sadeghnezhad

We study the behaviour of a specific system of relativistic elasticity in its own gravitational field: a static, spherically symmetric shell whose wall is of arbitrary thickness consisting of hyperelastic material. We give the system of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 CM Losert-Valiente Kroon