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Related papers: Axial $w$-modes of anisotropic neutron stars

200 papers

We study the inertial modes of slowly rotating, fully relativistic compact stars. The equations that govern perturbations of both barotropic and non-barotropic models are discussed, but we present numerical results only for the barotropic…

General Relativity and Quantum Cosmology · Physics 2009-11-07 K. H. Lockitch , J. L. Friedman , N. Andersson

This is the fourth paper in a series that attempt to put forward a consistent framework for modelling solid regions in neutron stars. Here we turn our attention to axial perturbations of spherically symmetric spacetimes using a gauge…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Max Karlovini , Lars Samuelsson

We calculate axisymmetric spheroidal modes of neutron stars magnetized with an axisymmetric poloidal magnetic field. We use polytropes of the indices $n\sim1$ as background equilibrium models of neutron stars where we ignore the deformation…

High Energy Astrophysical Phenomena · Physics 2017-12-06 Umin Lee

In the present paper we study the oscillations of fast rotating neutron stars with realistic equations of state (EoS) within the Cowling approximation. We derive improved empirical relations for gravitational wave asteroseismology with…

Solar and Stellar Astrophysics · Physics 2013-09-04 Daniela D. Doneva , Erich Gaertig , Kostas D. Kokkotas , Christian Krüger

We develop a numerical scheme for obtaining the $r$-mode oscillations of rapidly rotating relativistic stars. In the present scheme, we neglect all metric perturbations and only take account of the dynamics of the fluid in the background…

Astrophysics · Physics 2009-11-10 Shijun Yoshida , Shin'ichirou Yoshida , Yoshiharu Eriguchi

We constrain the fundamental-mode ($f$-mode) oscillation frequencies of nonrotating neutron stars using a phenomenological Gaussian process model for the unknown dense-matter equation of state conditioned on a suite of gravitational-wave,…

High Energy Astrophysical Phenomena · Physics 2026-01-01 Sailesh Ranjan Mohanty , Utkarsh Mali , H. C. Das , Bharat Kumar , Philippe Landry

The axial mode oscillations are examined for relativistic rotating stars with uniform angular velocity. Using the slow rotation formalism and the Cowling approximation, we have derived the equations governing the r-mode oscillations up to…

Astrophysics · Physics 2015-06-24 Yasufumi Kojima , Masayasu Hosonuma

We study the $f$-mode frequencies and damping times of nonrotating neutron stars (NS) in general relativity (GR) by solving the linearized perturbation equations, with the aim to establish "universal" relations that depend only weakly on…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Cecilia Chirenti , Gibran H. de Souza , Wolfgang Kastaun

We investigate the impact of the neutron-star matter equation of state on the $f$- and $p_1$-mode oscillations of neutron stars obtained within the Cowling approximation and linearized general relativity. The $f$- and $p_1$-mode oscillation…

Nuclear Theory · Physics 2022-10-10 Athul Kunjipurayil , Tianqi Zhao , Bharat Kumar , Bijay K. Agrawal , Madappa Prakash

A numerical method of mode analysis of rapidly rotating relativistic stellar models by the Cowling approximation is applied to rotating neutron stars with realistic equations of state. For selected equations of state, eigenvalues and…

Astrophysics · Physics 2009-10-30 S. Yoshida , Y. Eriguchi

By employing modified Chaplygin fluid prescription for the dark energy, we construct slowly rotating isotropic and anisotropic dark energy stars. The slow rotation is incorporated via general relativistic Hartle-Thorne formalism; whereas…

General Relativity and Quantum Cosmology · Physics 2024-07-26 O. P. Jyothilakshmi , Lakshmi J. Naik , V. Sreekanth

Dev (2002) discussed some exact solutions of anisotropic stars for special forms of TOV for constant energy density. Considering Bijalwan (2011) ansatz for charged perfect fluids we present here some exact solutions to the generalized TOV…

General Physics · Physics 2011-09-26 Naveen Bijalwan

It has been recently argued through numerical work that rotating stars with a high degree of differential rotation are dynamically unstable against bar-mode deformation, even for values of the ratio of rotational kinetic energy to…

Astrophysics · Physics 2009-06-23 Pablo Cerdá-Durán , Vicent Quilis , José A. Font

In this work, we study the impact of anisotropy on slowly rotating neutron stars by extending the Hartle-Thorne formalism in general relativity to include anisotropy in pressure up to second order in the angular velocity. We assess the…

General Relativity and Quantum Cosmology · Physics 2024-10-10 L. M. Becerra , E. A. Becerra-Vergara , F. D. Lora-Clavijo

We construct constant rest-mass sequences of equilibrium models of differentially rotating neutron stars which resemble binary neutron star post-merger remnants. For a more realistic description of the post-merger remnant, we impose that…

High Energy Astrophysical Phenomena · Physics 2026-03-03 Georgios Lioutas , Panagiotis Iosif , Andreas Bauswein , Nikolaos Stergioulas

In this work we revisit axial perturbations of spherically symmetric and non-rotating neutron stars. Although it has been object of many studies, it still offers new insights that are of potential interest for more realistic scenarios or in…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Sebastian H. Völkel , Kostas D. Kokkotas

We investigate damping and growth times of the f-mode for rapidly rotating stars and a variety of different polytropic equations of state in the Cowling approximation. We discuss the differences in the eigenfunctions of co- and…

Solar and Stellar Astrophysics · Physics 2011-05-10 Erich Gaertig , Kostas D. Kokkotas

We study non-linear axisymmetric pulsations of rotating relativistic stars using a general relativistic hydrodynamics code under the assumption of a conformal flatness. We compare our results to previous simulations where the spacetime…

Astrophysics · Physics 2009-11-11 Harald Dimmelmeier , Nikolaos Stergioulas , Jose A. Font

We investigate the non-linear coupling between radial and non-radial oscillations of static spherically symmetric neutron stars as a possible mechanism for the generation of gravitational waves that may lead to observable signatures. In…

General Relativity and Quantum Cosmology · Physics 2009-11-11 A. Passamonti , M. Bruni , L. Gualtieri , A. Nagar , C. F. Sopuerta

Neutron stars provide an excellent laboratory for physics under the most extreme conditions. Up to now, models of axisymmetric, stationary, differentially rotating neutron stars were constructed under the strong assumption of barotropicity,…

General Relativity and Quantum Cosmology · Physics 2019-12-11 Giovanni Camelio , Tim Dietrich , Miguel Marques , Stephan Rosswog