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In this paper, we develop a new relativistic compact stellar model for a spherically symmetric anisotropic matter distribution. The model has been obtained through generating a new class of solutions by invoking the Tolman {\em ansatz} for…

General Relativity and Quantum Cosmology · Physics 2020-11-25 Piyali Bhar , Shyam Das , Bikram Keshari Parida

We are now beginning to learn detailed information about cosmological parameters from the shapes of the matter and radiation power spectra, together with their relative normalization. As more high quality data are gathered from galaxy…

Astrophysics · Physics 2007-05-23 Douglas Scott

Interior structures of stellar objects might have small pressure anisotropy due to several reasons, including rotation and the presence of magnetic fields. Here, retaining the approximation of spherical symmetry, we study the possible role…

Solar and Stellar Astrophysics · Physics 2019-11-06 Shaswata Chowdhury , Tapobrata Sarkar

Within the metric formalism of $f(R)$ theories of gravity, where $R$ is the Ricci scalar, we study the hydrostatic equilibrium structure of compact stars with the inclusion of anisotropic pressure. In particular, we focus on the $f(R)=…

General Relativity and Quantum Cosmology · Physics 2022-07-11 Juan M. Z. Pretel , Sergio B. Duarte

We present model for anisotropic compact star under the general theory of relativity of Einstein. In the study a 4-dimensional spacetime has been considered which is embedded into the 5-dimensional flat metric so that the spherically…

General Physics · Physics 2018-08-01 S. K. Maurya , Saibal Ray , Shounak Ghosh , Sarbajit Manna , Smitha T. T

We present an anisotropic charged analogue of Kuchowicz (1971) solution of the general relativistic field equations in curvature coordinates by using simple form of electric intensity $E$ and pressure anisotropy factor $\Delta$ that involve…

General Relativity and Quantum Cosmology · Physics 2020-07-15 K N Singh , F Rahaman , N Pradhan , N Pant

The CMB anisotropy depends sensitively upon the slope and amplitude of primordial density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history, {\it etc.} We report…

Astrophysics · Physics 2009-09-25 J. Richard Bond , Richard L. Davis , Paul J. Steinhardt

In this article a class of anisotropic compact star is analysed in Heintzmann geometry. We have introduced the pressure anisotropy parameter ($\alpha$) and solved Einstein field equations to obtain stellar model. We have considered $g_{tt}$…

General Relativity and Quantum Cosmology · Physics 2023-09-21 B. Das , K. B. Goswami , P. K. Chattopadhyay

Upper limits for the mass-radius ratio and total charge are derived for stable charged general relativistic matter distributions. For charged compact objects the mass-radius ratio exceeds the value 4/9 corresponding to neutral stars.…

General Relativity and Quantum Cosmology · Physics 2009-11-07 M. K. Mak , Peter N. Dobson , T. Harko

Recently the small value of the cosmological constant and its ability to accelerate the expansion of the Universe is of great interest. We discuss the possibility of forming of anisotropic compact stars from this cosmological constant as…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Sk. Monowar Hossein , Farook Rahaman , Jayanta Naskar , Mehedi Kalam , Saibal Ray

In this paper, we study the impact of anisotropy on neutron stars with different equations of state, which have been modeled by a piecewise polytropic function with continuous sound speed. Anisotropic pressure in neutron stars is often…

High Energy Astrophysical Phenomena · Physics 2024-01-22 L. M. Becerra , E. A. Becerra-Vergara , F. D. Lora-Clavijo

In this work we evaluate the physical acceptability of relativistic anisotropic spheres modeled by two polytropic equations of state -- with the same newtonian limit -- commonly used to describe compact objects in General Relativity. We…

General Relativity and Quantum Cosmology · Physics 2021-02-02 D. Suárez-Urango , L. A. Núñez , H. Hernández

A class of general relativistic solutions in isotropic spherical polar coordinates are discussed which describe compact stars in hydrostatic equilibrium. The stellar models obtained here are characterized by four parameters, namely,…

Solar and Stellar Astrophysics · Physics 2015-06-17 Rumi Deb , Bikash Chandra Paul , Ramesh Tikekar

We investigate a compact spherically symmetric relativistic body with anisotropic particle pressure profiles. The distribution possesses characteristics relevant to modeling compact stars within the framework of general relativity. For this…

General Relativity and Quantum Cosmology · Physics 2018-02-28 S. K. Maurya , Ayan Banerjee , Sudan Hansraj

Spherically symmetric relativistic stars with the polytropic equation of state (EoS), which possess the local pressure anisotropy, are considered within the framework of general relativity. The generalized Lane-Emden equations are derived…

General Relativity and Quantum Cosmology · Physics 2018-01-12 A. A. Isayev

Motivation: Motivated by the growing interest in understanding the role of non-metricity in describing dense stellar systems, in this paper, we study compact stellar configurations within the framework of linear $f(Q)$ gravity. Methodology:…

General Relativity and Quantum Cosmology · Physics 2026-04-28 Arpita Ghosh , Abhishek Paul , Ranjan Sharma , Samstuti Chanda

This paper discusses a generalized model for compact stars, assumed to be anisotropic in nature due to the spherical symmetry and high density. After embedding the four-dimensional spacetime in a five-dimensional flat spacetime, which may…

General Physics · Physics 2018-03-09 S. K. Maurya , Debabrata Deb , Saibal Ray , P. K. F. Kuhfittig

The cosmological principle is a cornerstone of the standard cosmological model. However, recent observations suggest potential deviations from this assumption, hinting at a small anisotropic expansion. Such an expansion can arise from…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-23 Jose L. Palacios-Córdoba , J. Bayron Orjuela-Quintana , Gabriela A. Valencia-Zuñiga , César A. Valenzuela-Toledo

This thesis explores compact objects, particularly neutron stars, focusing on their properties, classification, and stability within the framework of general relativity. Two distinct studies are presented. The first study examines the…

General Relativity and Quantum Cosmology · Physics 2024-10-15 A. C. Khunt

The cosmic microwave background anisotropy is sensitive to the slope and amplitude of primordial energy density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history,…