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Related papers: Exact Gravastar Solution

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Based on perturbation theory, we present the exact first-order solution to the Einstein equations for the exterior static gravitational field of an isolated non-rotating star in a spatially finite universe having the topology of a flat…

General Relativity and Quantum Cosmology · Physics 2016-08-11 Frank Steiner

In this paper, we present three exact solutions to the Einstein field equations, each illustrating different black hole models. The first solution introduces a black hole with a variable equation of state, $P = k(r)\rho$, which can…

General Relativity and Quantum Cosmology · Physics 2025-01-03 Vitalii Vertogradov , Ali Övgün

A new solution for the endpoint of gravitational collapse is proposed. By extending the concept of Bose-Einstein condensation to gravitational systems, a cold, compact object with an interior de Sitter condensate phase and an exterior…

General Relativity and Quantum Cosmology · Physics 2023-02-16 Pawel O. Mazur , Emil Mottola

Gravastar models have recently been proposed as an alternative to black holes, mainly to avoid the pro\-ble\-ma\-tic issues associated with event horizons and singularities. In this work, a regular variety of gravastar models within the…

General Relativity and Quantum Cosmology · Physics 2019-03-28 Diego Julio Cirilo-Lombardo , Carlos Vigh

We study gravitational collapse of a spherically symmetric scalar field in Einstein-aether theory (general relativity coupled to a dynamical unit timelike vector field). The initial value formulation is developed, and numerical simulations…

General Relativity and Quantum Cosmology · Physics 2008-11-26 David Garfinkle , Christopher Eling , Ted Jacobson

We develop here a new procedure within Einstein's theory of gravity to generate equilibrium configurations that result as the final state of gravitational collapse from regular initial conditions. As a simplification, we assume that the…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Pankaj S. Joshi , Daniele Malafarina , Ramesh Narayan

We construct exact black hole solutions to Einstein gravity with nonlinear electrodynamic field. In these solutions, there are in general four parameters. They are physical mass, electric charge, cosmological constant and the coupling…

General Relativity and Quantum Cosmology · Physics 2020-05-27 Shuang Yu , Changjun Gao

Gravitational vacuum condensate stars, proposed as the endpoint of gravitational collapse consistent with quantum theory, are reviewed. Gravastars are cold, low entropy, maximally compact objects characterized by a surface boundary layer…

General Relativity and Quantum Cosmology · Physics 2023-11-28 Emil Mottola

We construct gravitational atoms including self-gravity, obtaining solutions of the Einstein-Klein-Gordon equations for a scalar field surrounding a non-rotating black hole in a quasi-stationary approximation. We resolve the region near the…

General Relativity and Quantum Cosmology · Physics 2025-10-23 Miguel Alcubierre , Juan Barranco , Argelia Bernal , Juan Carlos Degollado , Alberto Diez-Tejedor , Miguel Megevand , Darío Núñez , Olivier Sarbach

In this Letter we derive the gravity field equations by varying the action for an ultraviolet complete quantum gravity. Then we consider the case of a static source term and we determine an exact black hole solution. As a result we find a…

General Relativity and Quantum Cosmology · Physics 2011-02-22 Leonardo Modesto , John W. Moffat , Piero Nicolini

In this article, we are reporting for the first time the existence of gravastar configurations in the framework of K(R,T)-gravity, which can be treated as an alternative to a black hole (Mazur and Mottola). This strengthens how much this…

General Relativity and Quantum Cosmology · Physics 2023-08-22 GRP Teruel , Ksh. Newton Singh , Tanmoy Chowdhury , Farook Rahaman , Monimala Mondal

An open problem in general relativity has been to construct an asymptotically flat solution to a reasonable Einstein-matter system containing a black hole in the future and yet past-causally geodesically complete, in particular, containing…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Mihalis Dafermos

In this paper, we show that it is possible to have pure quantum gravastar solution to the quantum improved Einstein equations. Such an object is essentially a gravastar in which the thin layer of matter is replaced by quantum effects. The…

General Relativity and Quantum Cosmology · Physics 2022-08-30 Raihaneh Moti , Ali Shojai

We report exact black hole solutions in asymptotically flat or (A)dS four-dimensional spacetime with a conformally coupled self-interacting scalar field in $f(R)$ gravity. We first consider the asymptotically flat model $f(R) = R -2\alpha…

General Relativity and Quantum Cosmology · Physics 2021-10-25 Thanasis Karakasis , Eleftherios Papantonopoulos , Zi-Yu Tang , Bin Wang

In this paper, we investigate the numerical solutions for spherically symmetric situations in Einstein cubic gravity. In addition to the previously found black hole solutions, we uncover a new class of solutions that lack horizons. Due to…

General Relativity and Quantum Cosmology · Physics 2024-10-08 Yong-Qiang Wang

It is well known that the concept of black hole has been considered very fascinating by scientists even before the introduction of Einstein's general relativity. They should be the final result of an irreversible gravitational collapse of…

General Relativity and Quantum Cosmology · Physics 2011-10-20 Christian Corda , Herman J. Mosquera Cuesta

It is formulated a new 'anholonomic frame' method of constructing exact solutions of Einstein equations with off--diagonal metrics in 4D and 5D gravity. The previous approaches and results are summarized and generalized as three theorems…

High Energy Physics - Theory · Physics 2007-05-23 Sergiu I. Vacaru

One of the main challenges in astronomy is the direct observation of black holes. However, differentiating them from black holes through photon observations can be difficult if Ultra-Compact Objects with unstable circular photon orbits…

General Relativity and Quantum Cosmology · Physics 2026-05-06 M. A. Anacleto , A. T. N. Silva , L. Casarini

We study static, spherically symmetric black hole solutions of the Einstein equations with a positive cosmological constant and a conformally coupled self interacting scalar field. Exact solutions for this model found by Mart{\'\i}nez,…

High Energy Physics - Theory · Physics 2008-11-26 Gustavo Dotti , Reinaldo J. Gleiser , Cristian Martinez

In this paper, we have extended the idea of gravitational Bose-Einstein condensate star (gravastar) to charged gravastar system and explored the role of charge in gravastar formation and its properties. We have used the most general line…

General Relativity and Quantum Cosmology · Physics 2023-08-25 D. Bhattacharjee , P. K. Chattopadhyay