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Related papers: Tolman IV fluid sphere in bigravity

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This paper investigates the viability and stability of anisotropic compact stars in the framework of $f(\mathcal{R},\mathrm{T}^{2})$ theory ($\mathcal{R}$ is the Ricci scalar and…

General Relativity and Quantum Cosmology · Physics 2023-05-31 M. Sharif , Sana Manzoor

Exact cosmological solutions are obtained for a five dimensional inhomogeneous fluid distribution along with a Brans-Dicke type of scalar field. The set includes varied forms of matter field including $\rho+p=0$, where p is the 3D isotropic…

General Relativity and Quantum Cosmology · Physics 2009-11-10 D. Panigrahi , Y. Z. Zhang , S. Chatterjee

In this paper, we study the dynamical irregularity of the locally anisotropic spherical fluids in the context of Einstein-Gauss-Bonnet theory. We aim to describe the causes of energy-density irregularity of self-gravitating fluids and…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Z. Yousaf , Kazuharu Bamba , Mansoor Alshehri , A. Farhat

Oscillating moduli fields can support a cosmological scaling solution in the presence of a perfect fluid when the scalar field potential satisfies appropriate conditions. We examine when such conditions arise in higher-dimensional,…

High Energy Physics - Theory · Physics 2008-11-26 James E. Lidsey , Karim A. Malik

Considering Vaidya-Tikekar metric, we obtain a class of solutions of the Einstein-Maxwell equations for a charged static fluid sphere. The physical 3-space (t=constant) here is described by pseudo-spheroidal geometry. The relativistic…

Solar and Stellar Astrophysics · Physics 2015-06-05 Pradip Kr. Chattopadhyay , Rumi Deb , Bikash Chandra Paul

In the context of whether a massive compact object recently observed in the GW190814 event is a neutron star (NS) or not, we have studied the role of the parameters $\kappa$ and $\Lambda_c$ of the Eddington-inspired Born-Infeld (EiBI)…

General Relativity and Quantum Cosmology · Physics 2021-10-07 I. Prasetyo , H. Maulana , H. S. Ramadhan , A. Sulaksono

We express the Einstein-Vlasov system in spherical symmetry in terms of a dimensionless momentum variable $z$ (radial over angular momentum). This regularises the limit of massless particles, and in that limit allows us to obtain a reduced…

General Relativity and Quantum Cosmology · Physics 2017-01-04 Carsten Gundlach

Quasi-local variables, i.e. quantities whose values can be derived from physics accessible within an arbitrarily small neighborhood of a spacetime point, are used to construct the equation of state (EoS) for the anisotropic fluid in the…

General Relativity and Quantum Cosmology · Physics 2011-01-20 Dubravko Horvat , Sasa Ilijic , Anja Marunovic

We investigate the propagation of gravitational waves in the context of fourth order gravity nonminimally coupled to a massive scalar field. Using the damping of the orbital period of coalescing stellar binary systems, we impose constraints…

General Relativity and Quantum Cosmology · Physics 2015-07-10 Gaetano Lambiase , Mairi Sakellariadou , Antonio Stabile , Arturo Stabile

In this paper, we investigate Bianchi type-$VI$ cosmological model for the universe filled with dark energy and viscous fluid in the presence of cosmological constant. Also, we show accelerating expansion of the universe by drawing volume…

General Relativity and Quantum Cosmology · Physics 2013-08-29 J. Sadeghi , Ali R. Amani , N. Tahmasbi

The present work contains a discussion on compact stellar body that is influenced by the effects electromagnetic fields. We have tried to discuss a solution of Einstein-Maxwell field equation with the interpretation of Buchdahl spacetime…

General Relativity and Quantum Cosmology · Physics 2022-04-05 Manuel Malaver de la Fuente , Rajan Iyer , Alokananda Kar , Shouvik Sadhukhan , Sudhaker Upadhyay , Ertan Gudekli

In this paper, we have presented a compact object model in the framework of Einstein-Gauss-Bonnet gravity (EGB) with a linear equation of state considering a metric potential proposed for Buchdahl (1959). The new obtained models satisfy all…

General Relativity and Quantum Cosmology · Physics 2023-01-24 Manuel Malaver , Rajan Iyer , Israr Khan

We examine the dynamics of a rotating viscous fluid following an abrupt change in the angular velocity of the solid bounding surface. We include the effects of a density stratification and compressibility which are important in…

Astrophysics · Physics 2014-10-13 Mark Abney , Richard I Epstein

This research paper investigates the impact of non-metricity and matter source on the geometry of charged spheres in the presence of anisotropic matter configuration. We use a specific model of extended symmetric teleparallel theory to…

General Relativity and Quantum Cosmology · Physics 2024-12-03 M. Zeeshan Gul , Faisal Javed , M. Sharif , Shalan Alkarni

Several other factors, besides the intrinsic local geometry, contribute to give a meaning to a space-time model. The simplest example comes from comparing Minkowski's and Milne's model, that both have a null Riemann tensor. We add to these…

General Relativity and Quantum Cosmology · Physics 2007-12-05 Ll. Bel

A new scheme for testing nuclear matter equations of state (EsoS) at high densities using constraints from neutron star phenomenology and a flow data analysis of heavy-ion collisions is suggested. An acceptable EoS shall not allow the…

We present a systematic investigation of the cosmological constant effects in compact stars interiors in the framework of Einstein's gravity. Consideration of a cosmological constant $\Lambda$ in compact stars is motivated by the mechanism…

High Energy Astrophysical Phenomena · Physics 2019-02-05 Noshad Khosravi Largani , David E. Alvarez-Castillo

It is shown -- using a FRW model with ${\bf S}^3 \times {\bf S}^6$ as spatial sections and a positive cosmological constant -- that classical signature change implies a new compactification mechanism. The internal scale factor is of the…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Franz Embacher

The primary objective of this work is to study the dynamical characteristics of an anisotropic compact star model with spherical symmetry. This investigation is conducted in the framework of $f(Q)$ modified gravity. To simplify the…

General Relativity and Quantum Cosmology · Physics 2023-12-29 G. Mustafa , Allah Ditta , Saadia Mumtaz , S. K. Maurya , Değer Sofuoğlu

The concept of dark energy can be a candidate for preventing the gravitational collapse of compact objects to singularities. According to the usefulness of gravity's rainbow in UV completion of general relativity (by providing a new…

General Relativity and Quantum Cosmology · Physics 2022-10-25 A. Bagheri Tudeshki , G. H. Bordbar , B. Eslam Panah