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Related papers: Nonradial instabilities in anisotropic neutron sta…

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We investigate the impact of pressure anisotropy on the structural and geometric properties of neutron stars within general relativity, focusing primarily on the phenomenological Bowers-Liang (BL) model, and comparing selected results with…

General Relativity and Quantum Cosmology · Physics 2026-05-08 A. C. Khunt , K. Yavuz Ekşi , P. C. Vinodkumar

We study the time evolution of non-axisymmetric linear perturbations of a rotating magnetised neutron star, whose magnetic field is multipolar and purely poloidal. The background stellar configurations are generated self-consistently,…

Solar and Stellar Astrophysics · Physics 2015-05-20 S. K. Lander , D. I. Jones

The aim of this paper is to clarify the stabilities of neutron stars with strong toroidal magnetic fields against non-axisymmetric perturbation. The motivation comes from the fact that super magnetized neutron stars of $\sim 10^{15}$G,…

High Energy Astrophysical Phenomena · Physics 2012-08-21 Kenta Kiuchi , Shijun Yoshida , Masaru Shibata

We investigate the dynamical stability of relativistic, differentially rotating, quasi-toroidal models of neutron stars through hydrodynamical simulations in full general relativity. We find that all quasi-toroidal configurations studied in…

High Energy Astrophysical Phenomena · Physics 2019-08-21 Pedro L. Espino , Vasileios Paschalidis , Thomas W. Baumgarte , Stuart L. Shapiro

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

We investigate inertial mode oscillations of slowly and uniformly rotating, isentropic, Newtonian stars. Inertial mode oscillations are induced by the Coriolis force due to the star's rotation, and their characteristic frequencies are…

Astrophysics · Physics 2016-08-30 Shijun Yoshida , Umin Lee

The anisotropy of pressure arises due to the various complex phenomena that happen inside the neutron star (NS). In this study, we calculate the degree of anisotropy inside the NS using the scalar pressure anisotropy model. Macroscopic…

High Energy Astrophysical Phenomena · Physics 2023-04-06 H. C. Das , Jeet Amrit Pattnaik , S. K. Patra

Binary neutron star mergers produce massive, hot, rapidly differentially rotating neutron star remnants; electromagnetic and gravitational wave signals associated with the subsequent evolution depend on the stability of these remnants.…

We consider the evolution in full general relativity of a family of linearly unstable isolated spherical neutron stars under the effects of very small, perturbations as induced by the truncation error. Using a simple ideal-fluid equation of…

General Relativity and Quantum Cosmology · Physics 2011-07-18 David Radice , Luciano Rezzolla , Thorsten Kellermann

Quasi-normal modes of neutron stars are an exciting prospect for analyzing the internal composition of NSs and studying matter at high densities. In this work, we focus on studying the $f$- and $p$- quadrupolar oscillation modes, which…

General Relativity and Quantum Cosmology · Physics 2024-12-02 Pratik Thakur , Sagnik Chatterjee , Kamal Krishna Nath , Ritam Mallick

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

Tensor-multi-scalar theories (TMST) are among the most natural generalizations of Einstein's theory, they are mathematically self-consistent and free from pathologies. They pass through all the known observations but contrary to standard…

General Relativity and Quantum Cosmology · Physics 2020-09-02 Daniela D. Doneva , Stoytcho S. Yazadjiev , Kostas D. Kokkotas

In [Leung et al., Phys. Rev. D 84, 107301 (2011)], we presented our results on using a general relativistic two-fluid formalism to study the hydrostatic equilibrium configuration of an admixture of degenerate dark matter and normal nuclear…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-04 S. -C. Leung , M. -C. Chu , L. -M. Lin

We study non-axisymmetric oscillations of rapidly and differentially rotating relativistic stars in the Cowling approximation. Our equilibrium models are sequences of relativistic polytropes, where the differential rotation is described by…

Solar and Stellar Astrophysics · Physics 2010-04-22 Christian Krüger , Erich Gaertig , Kostas D. Kokkotas

We use gravitational wave (GW) and electromagnetic (EM) observations of GW170817 to constrain the extent of pressure anisotropy in it. While it is quite likely that the pressure inside a neutron star is mostly isotropic, certain physical…

General Relativity and Quantum Cosmology · Physics 2019-05-08 Bhaskar Biswas , Sukanta Bose

The frequencies of quasi-periodic oscillations around neutron stars are believed to be related to characteristic frequencies in the gravitational fields of the compact objects. In different variability models, these include the Keplerian,…

Astrophysics · Physics 2007-05-23 Simon DeDeo , Dimitrios Psaltis

Next-generation gravitational-wave detectors are expected to constrain the properties of extreme density matter via observations of static and dynamical tides in binary neutron star inspirals. The required modelling is straightforward in…

General Relativity and Quantum Cosmology · Physics 2025-04-10 Shanshan Yin , Nils Andersson , Fabian Gittins

$r$-mode oscillations in rotating neutron stars are a source of continuous gravitational radiation. We investigate the excitation of $r$-modes by the mechanical impact on the neutron star surface of stochastically accreted clumps of matter,…

High Energy Astrophysical Phenomena · Physics 2025-02-20 Wenhao Dong , Andrew Melatos

Neutron stars are compact, relativistic bodies that host several extremes of modern physics. An exciting development in recent years has been the opportunity to probe this exotic physics by observing compact-binary coalescences using…

General Relativity and Quantum Cosmology · Physics 2025-07-10 Fabian Gittins , Nils Andersson , Shanshan Yin

Tidal deformabilities are one of the observable quantities characterizing neutron stars, which are strongly associated with the stellar compactness, the ratio of the stellar mass to the radius. In addition to the tidal deformability, the…

High Energy Astrophysical Phenomena · Physics 2026-02-24 Hajime Sotani