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Related papers: Tolman IV fluid sphere in bigravity

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We consider static spherically symmetric self-gravitating configurations of the perfect fluid within the framework of the torsion-based extended theory of gravity. In particular, we use the covariant formulation of $f(T)$ gravity with $f(T)…

General Relativity and Quantum Cosmology · Physics 2018-10-03 Sasa Ilijic , Marko Sossich

This article aims to investigate various anisotropic stellar models in the background of $f(\mathcal{R},\mathcal{T},\mathcal{Q})$ gravity, where $\mathcal{Q}=\mathcal{R}_{\varphi\vartheta}\mathcal{T}^{\varphi\vartheta}$. In this regard, we…

General Relativity and Quantum Cosmology · Physics 2024-10-10 M. Sharif , Tayyab Naseer

For a set of equation of state (EoS) models involving interacting strange quark matter, characterized by an effective bag constant (B_eff) and a perturbative QCD corrections term (a_4), we construct fully general relativistic equilibrium…

High Energy Astrophysical Phenomena · Physics 2016-02-03 Sudip Bhattacharyya , Ignazio Bombaci , Domenico Logoteta , Arun V. Thampan

We develop a new model for a spherically symmetric dark matter fluid sphere containing two regions: {\bf (i)} Isotropic inner region with constant density and {\bf (ii)} Anisotropic outer region. We solve the system of field equation by…

General Relativity and Quantum Cosmology · Physics 2020-12-02 Shyam Das , Nayan Sarkar , Monimala Mondal , Farook Rahaman

We model compact objects of known stellar mass and radius made of isotropic matter within Einstein's gravity. The interior solution describing hydrostatic equilibrium we are using throughout the manuscript corresponds to the Tolman IV exact…

General Relativity and Quantum Cosmology · Physics 2024-08-29 Grigoris Panotopoulos

In the version \cite{Fiziev14} of this paper we presented for the first time the basic equations and relations for relativistic static spherically symmetric stars (SSSS) in the model of minimal dilatonic gravity (MDG). This model is {\em…

General Relativity and Quantum Cosmology · Physics 2017-08-14 Plamen P Fiziev

We consider warped compactifications in (4+d)-dimensional theories, with four dimensional de Sitter dS_4 vacua (with Hubble parameter H) and with a compact internal space. After introducing a gauge-invariant formalism for the generic metric…

High Energy Physics - Theory · Physics 2010-11-19 Carlo Contaldi , Lev Kofman , Marco Peloso

In this article, we study the 1 + 3 dimensional relativistic Euler equations on a pre-specified conformally flat expanding spacetime background with spatial slices that are diffeomorphic to $\mathbb{R}^3.$ We assume that the fluid verifies…

Analysis of PDEs · Mathematics 2015-06-03 Jared Speck

The properties of strange quark stars are studied within the quasi-particle model. Taking into account the chemical equilibrium and charge neutrality, the EOS of $ (2+1) $-flavor quark matter is obtained. We illustrate the parameter spaces…

High Energy Physics - Phenomenology · Physics 2020-11-10 Wen-Hua Cai , Qing-Wu Wang

Multidimensional cosmological models with a higher dimensional space-time manifold are investigated under dimensional reduction. In the Einstein conformal frame, the effective potential for the internal scale factors is obtained. The stable…

General Relativity and Quantum Cosmology · Physics 2007-05-23 U. Guenther , S. Kriskiv , A. Zhuk

Employing $f(T)$ gravity, where $T$ is the torson, we have developed a new model of an anisotropic compact star in this work. Tolman-Kuchowicz (TK) metric potential has been used to solve the set of field equations. Furthermore, the…

General Relativity and Quantum Cosmology · Physics 2023-04-12 Piyali Bhar

Alternative gravity theory is currently an incredibly significant technique for addressing some enduring experimental difficulties, such as the universe's dark region. They may also be employed in celestial cosmology, producing results that…

General Relativity and Quantum Cosmology · Physics 2024-05-01 Tayyaba Naz , Adnan Malik , Zenab Ramay

The equilibrium configurations of slowly rotating anisotropic self-gravitating fluids are computed using the extended Hartle structure equations, including anisotropic effects, derived in our previous paper. We focus on the so-called…

General Relativity and Quantum Cosmology · Physics 2025-10-20 Philip Beltracchi , Camilo Posada

We consider the gravitational Euler-Poisson system with a linear equation of state on an expanding cosmological model of the Universe. The expansion of the spatial sections introduces an additional dissipating effect in the Euler equation.…

Analysis of PDEs · Mathematics 2025-12-23 David Fajman , Maciej Maliborski , Maximilian Ofner , Todd Oliynyk , Zoe Wyatt

In this paper a new class of exact solutions of Einstein's field equations for compact stars with charged distributions is obtained on the basis of pseudo-spheroidal spacetime characterized by the metric potential…

General Physics · Physics 2015-11-16 V. O. Thomas , D. M. Pandya

We derive upper and lower limits for the mass-radius ratio of spin-fluid spheres in Einstein-Cartan theory, with matter satisfying a linear barotropic equation of state, and in the presence of a cosmological constant. Adopting a spherically…

General Relativity and Quantum Cosmology · Physics 2018-06-25 Christian G. Boehmer , Piyabut Burikham , Tiberiu Harko , Matthew J. Lake

We investigate the thermal Casimir effect for a massless scalar field in the curved spacetime of a neutron star within the Thermo Field Dynamics (TFD) formalism. Starting from the renormalized energy-momentum tensor, we generalize the…

General Relativity and Quantum Cosmology · Physics 2025-12-23 K. E. L. de Farias , M. A. Anacleto , Rafael A. Batista , Iver Brevik , F. A. Brito , E. Passos , Amilcar R. Queiroz , Lázaro L. Sales

We consider plane-symmetric spacetimes satisfying Einstein's field equations with positive cosmological constant, when the matter is a fluid whose pressure is equal to its mass-energy density (i.e. a so-called stiff fluid). We study the…

General Relativity and Quantum Cosmology · Physics 2012-05-01 Philippe G. LeFloch , Sophonie B. Tchapnda

This review covers several recent developments in the physics of dense QCD with an emphasis on the impact of multiple phase transitions on astrophysical manifestations of compact stars. It is conjectured that pair-correlated quark matter in…

Nuclear Theory · Physics 2023-07-18 Armen Sedrakian

We propose a new doorway to study the interplay between equations of state of dense matter and compact stars in gauge/gravity correspondence. For this we construct a bulk geometry near the boundary of five-dimensional spacetime. By solving…

High Energy Physics - Phenomenology · Physics 2015-06-05 Kyung Kiu Kim , Youngman Kim , Ik Jae Shin