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Related papers: Gravastars in a Non-minimally Coupled Gravity with…

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We consider neutron star configurations in the scalar-tensor theory of gravity with the coupling between the kinetic term of a scalar field and the Einstein tensor (such the model is a subclass of Horndeski gravity). Neutron stars in this…

General Relativity and Quantum Cosmology · Physics 2023-01-18 Pavel E. Kashargin , Sergey V. Sushkov

We establish a new self-consistent system of equations for the gravitational and electromagnetic fields. The procedure is based on a non-minimal non-linear extension of the standard Einstein-Hilbert-Maxwell action. General properties of a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Alexander B. Balakin , José P. S. Lemos

This paper examines the structure of a gravitationally vacuum star (also known as gravastar) in the background of ${f}(\Re,\mathcal{T}^{2})$ theory. This hypothetical object can be treated as a substitute of a black hole, with three…

General Relativity and Quantum Cosmology · Physics 2025-09-16 M. Sharif , Saba Naz

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

We propose a stellar model under the $f(\mathbb{T},\mathcal{T})$ gravity following Mazur-Mottola's conjecture [Mazur (2001), Mazur (2004)] known as gravastar which is generally believed as a viable alternative to black hole. The gravastar…

General Relativity and Quantum Cosmology · Physics 2020-03-09 Shounak Ghosh , A. D. Kanfon , Amit Das , M. J. S. Houndjo , I. G. Salako , Saibal Ray

We investigate static, spherically symmetric solutions in Einstein-scalar-Gauss-Bonnet gravity non-minimally coupled to a massless real scalar field, both in vacuum and in the presence of fermionic matter. Focusing on a specific quadratic…

General Relativity and Quantum Cosmology · Physics 2025-11-03 Roberto D. Alba Q. , Javier Chagoya , Armando A. Roque

The properties of a star with constant positive energy density inside (as for the Schwarzschild interior geometry) and a negative pressure are investigated, using a static conformally flat spacetime. Because of the negative pressure, the…

General Relativity and Quantum Cosmology · Physics 2025-04-08 Hristu Culetu

We consider the sector of Horndeski's gravity characterized by the coupling between the kinetic scalar field term and the Einstein tensor. We numerically construct neutron star configurations where the external geometry is identical to the…

General Relativity and Quantum Cosmology · Physics 2015-09-02 Adolfo Cisterna , Térence Delsate , Massimiliano Rinaldi

In the present paper we investigate non-perturbatively and self-consistently the structure of neutron stars in $R$-squared gravity by simultaneously solving the interior and exterior problem. The mass-radius relations are obtained for…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Stoytcho S. Yazadjiev , Daniela D. Doneva , Kostas D. Kokkotas , Kalin V. Staykov

A striking characteristic of non-Schwarzschild vacuum exteriors is that they contain not only the total gravitational mass of the source, but also an {\it arbitrary} constant. In this work, we show that the constants appearing in the…

General Relativity and Quantum Cosmology · Physics 2014-04-10 J. Ponce de Leon

Astrophysical black holes arise as exact solutions of the Einstein field equations. Therefore, any alternative, such as a gravastar, must satisfy the same level of mathematical rigor and internal consistency. A physically viable gravastar…

General Relativity and Quantum Cosmology · Physics 2026-04-14 Farook Rahaman , Bikramarka S. Choudhury , Aritra Sanyal , Anikul Islam , Bidisha Samanta

This paper discusses the configuration of gravitational vacuum star or gravastar with the impact of geometry and matter coupling present in $f(R,T)$ gravity. The gravastar is also conceptualized as a substitute for a black hole which is…

General Relativity and Quantum Cosmology · Physics 2020-12-07 M. Sharif , Arfa Waseem

This study investigates the gravastars in the framemwork of Rastall theory of gravity in generalised cylindrically symmetric space-time. Following the Mazur-Mottola hypothesis (P. O. Mazur and E. Mottola, Universe {\bf 9}, 88 (2023)),…

General Relativity and Quantum Cosmology · Physics 2025-05-14 Debadri Bhattacharjee , Pradip Kumar Chattopadhyay

In this paper, we investigate the effects of electromagnetic field on the isotropic spherical gravastar models in metric $f(R,T)$ gravity. For this purpose, we have explored singularity-free exact models of relativistic spheres with a…

General Relativity and Quantum Cosmology · Physics 2020-03-03 Z. Yousaf , Kazuharu Bamba , M. Z. Bhatti , U. Ghafoor

Gravastars, theoretical alternatives to black holes, have captured the interest of scientists in astrophysics due to their unique properties. This paper aims to further investigate the exact solution of a novel gravastar model based on the…

General Relativity and Quantum Cosmology · Physics 2024-05-01 Faisal Javed , Ji Lin

We calculate static and spherically symmetric solutions for the Rastall modification of gravity to describe Neutron Stars (NS). The key feature of the Rastall gravity is the non-conservation of the energy-momentum tensor proportionally to…

General Relativity and Quantum Cosmology · Physics 2016-10-24 A. M. Oliveira , H. E. S. Velten , J. C. Fabris , L. Casarini

Direct observation of black holes is one of the grand challenges in astronomy. If there are super-compact objects which possess unstable circular orbits of photons, however, it may be difficult to distinguish them from black holes by…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Nobuyuki Sakai , Hiromi Saida , Takashi Tamaki

In this paper we construct a charged thin-shell gravastar model within the context of noncommutative geometry. To do so, we choose the interior of the nonsingular de Sitter spacetime with an exterior charged noncommutative solution by…

General Relativity and Quantum Cosmology · Physics 2017-08-24 Ali Övgün , Ayan Banerjee , Kimet Jusufi

In this study, we investigate the features of a charged gravastar within the framework of $f(\mathbb{Q})$ gravity ($\mathbb{Q}$ represents non-metricity) using the Finch-Skea metric. This metric is applied to both the interior and shell…

General Relativity and Quantum Cosmology · Physics 2025-03-11 M. Sharif , Madiha Ajmal

Soft Gamma-Ray Repeaters and Anomalous X-Ray Pulsars are extreme manifestations of the most magnetized neutron stars: magnetars. The phenomenology of their emission and spectral properties strongly support the idea that the magnetospheres…

High Energy Astrophysical Phenomena · Physics 2015-06-23 A. G. Pili , N. Bucciantini , L. Del Zanna