English
Related papers

Related papers: Rapidly rotating compact stars in Rastall's gravit…

200 papers

Within general relativity, we construct sequences of rapidly rotating Dirac stars consisting of a spinor fluid described by an effective equation of state. We find the physically relevant domain of stable configurations and calculate their…

General Relativity and Quantum Cosmology · Physics 2022-07-15 Vladimir Dzhunushaliev , Vladimir Folomeev , Nassurlla Burtebayev

The current model explores spherically symmetric anisotropic compact stars within the Rastall theory of gravity. By employing the Krori and Barua metric ansatz (K.D. Krori and J. Barua, J. Phys. A: Math. Gen. 8 (1975) 508), we derive a set…

General Relativity and Quantum Cosmology · Physics 2025-05-29 Sourav Biswas , Debadri Bhattacharjee , Pradip Kumar Chattopadhyay

We revisit the problem of inertial r-modes in stratified stars, drawing on a more precise description of the composition stratification in a mature neutron star. The results highlight issues with the traditional approach to the problem,…

General Relativity and Quantum Cosmology · Physics 2023-05-23 Nils Andersson , Fabian Gittins

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 study self-gravitating stars in the bootstrapped Newtonian picture for polytropic equations of state. We consider stars that span a wide range of compactness values. Both matter density and pressure are sources of the gravitational…

General Relativity and Quantum Cosmology · Physics 2020-11-25 Roberto Casadio , Octavian Micu

Non-axisymmetric oscillations of differentially rotating stars are studied using both slow rotation and Cowling approximation. The equilibrium stellar models are relativistic polytropes where differential rotation is described by the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Andrea Passamonti , Adamantios Stavridis , Kostas Kokkotas

Non-axisymmetric oscillations of rapidly rotating relativistic stars are studied using the Cowling approximation. The oscillation spectra have been estimated by Fourier transforming the evolution equations describing the perturbations. This…

General Relativity and Quantum Cosmology · Physics 2009-09-29 Erich Gaertig , Kostas D. Kokkotas

These lecture notes are intended to introduce the theory of rotating stars in general relativity. The focus is put on the theoretical foundations, with a detailed discussion of the spacetime symmetries, the choice of coordinates and the…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Eric Gourgoulhon

We study the dynamical instability against bar-mode deformation of differentially rotating stars. We performed numerical simulation and linear perturbation analysis adopting polytropic equations of state with the polytropic index $n=1$. It…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Masaru Shibata , Shigeyuki Karino , Yoshiharu Eriguchi

In static and spherically symmetric spacetime, we solve the Einstein Maxwell equations. The effective gravitational potential and the electric field for charged anisotropic fluid are defined in terms of two free parameters. For such…

Solar and Stellar Astrophysics · Physics 2017-02-20 Safiqul Islam , Satadal Datta , Tapas K Das

A brief review of the stability of rotating relativistic stars is followed by a more detailed discussion of recent work on an instability of r-modes, modes of rotating stars that have axial parity in the slow-rotation limit. These modes may…

General Relativity and Quantum Cosmology · Physics 2008-11-26 John L. Friedman , Keith H. Lockitch

A theoretical study of some electrodynamic features of a region close to a {\it slowly-rotating} magnetized relativistic star is performed. To be a little more specific, based on the solution-generating method given by Wald, the magnetic…

Astrophysics · Physics 2007-05-23 Hongsu Kim , Hyung Mok Lee , Chul H. Lee , Hyun Kyu Lee

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

We formulate within a generalized distributional approach the treatment of the stability against radial perturbations for both neutral and charged stratified stars in Newtonian and Einstein's gravity. We obtain from this approach the…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Jonas P. Pereira , Jorge A. Rueda

In the modern era of abundant X-ray detections and the increasing momentum of gravitational waves astronomy, tests of General Relativity in strong field regime become increasingly feasible and their importance for probing gravity cannot be…

General Relativity and Quantum Cosmology · Physics 2020-09-25 Victor I. Danchev , Daniela D. Doneva , Stoytcho S. Yazadjiev

We study the radial pulsation frequencies of slowly rotating neutron stars in general relativistic formalism using realistic equations of state. It is found that the pulsation frequencies are always an increasing function of rotation rate.…

Astrophysics · Physics 2007-05-23 P. K. Sahu , A. R. Prasanna

Quasi-equilibrium models of rapidly rotating triaxially deformed stars are computed in general relativistic gravity, assuming a conformally flat spatial geometry (Isenberg-Wilson-Mathews formulation) and a polytropic equation of state.…

Astrophysics · Physics 2009-01-08 Xing Huang , Charalampos Markakis , Noriyuki Sugiyama , Koji Uryu

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 study secular stability against a quasi-radial oscillation for rigidly rotating stars with soft equations of state in general relativity. The polytropic equations of state with polytropic index $n$ between 3 and 3.05 are adopted for…

Astrophysics · Physics 2009-11-10 Masaru Shibata

We present a self-consistent, relativistic model of rapidly rotating neutron stars describing their exterior gravitational field. This is achieved by matching the new solution of Einstein's field equations found by Manko et al. (2000) and…

Astrophysics · Physics 2009-11-07 Matthias Stute , Max Camenzind