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Related papers: Nonradial instabilities in anisotropic neutron sta…

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In this article, we investigate inertial modes of rigidly rotating neutron stars, i.e. modes for which the Coriolis force is dominant. This is done using the assumption of a fixed spacetime (Cowling approximation). We present frequencies…

Astrophysics · Physics 2008-11-26 Wolfgang Kastaun

Radiation-pressure instability was identified soon after the seminal classical accretion disk models of Shakura-Sunyaev and Novikov-Thorne, yet its full implications remain an active area of investigation. These models form the backbone of…

High Energy Astrophysical Phenomena · Physics 2025-12-10 Agnieszka Janiuk , Bozena Czerny , Pulkit Ojha , Yuri Cavecchi , Federico Vincentelli

We study quasinormal $f-$mode oscillations in neutron star(NS) interiors within the linearized General Relativistic formalism. We utilize approximately 9000 nuclear Equations of State (EOS) using spectral representation techniques,…

High Energy Astrophysical Phenomena · Physics 2024-04-30 Debanjan Guha Roy , Tuhin Malik , Swastik Bhattacharya , Sarmistha Banik

Radial oscillations provide a direct probe of the stability and compressibility of neutron stars and are highly sensitive to the equation of state of dense matter. In this work, we investigate the impact of antikaon condensates on the…

Nuclear Theory · Physics 2026-01-29 Manisha Kumari , Sujan Kumar Roy , Soumen Podder , Suman Pal , Gargi Chaudhuri

We investigate the radial stability of neutron stars under conditions where their composition may or may not remain in chemical equilibrium during oscillations. Using different equations of state that include nucleons, hyperons, and/or…

High Energy Astrophysical Phenomena · Physics 2024-12-31 Martin O. Canullan-Pascual , German Lugones , Milva G. Orsaria , Ignacio F. Ranea-Sandoval

In this review we summarize the current understanding of the gravitational-wave driven instability associated with the so-called r-modes in rotating neutron stars. We discuss the nature of the r-modes, the detailed mechanics of the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 N. Andersson , K. D. Kokkotas

We perform a linear stability analysis of the axisymmetric, relativistic, self-similar isothermal disk against non-axisymmetric perturbations. Two sets of neutral modes are discovered. The first set corresponds to marginally unstable…

Astrophysics · Physics 2009-11-10 Mike J. Cai , Frank H. Shu

Pulsars are unique astrophysical laboratories because of their clock-like timing precision, providing new ways to test general relativity and detect gravitational waves. One impediment to high-precision pulsar timing experiments is timing…

Solar and Stellar Astrophysics · Physics 2015-05-20 Rachel Rosen , Maura A. McLaughlin , Susan E. Thompson

We obtain well behaved interior solutions describing hydrostatic equilibrium of anisotropic relativistic stars in scale-dependent gravity, where Newton's constant is allowed to vary with the radial coordinate throughout the star. Assuming…

General Relativity and Quantum Cosmology · Physics 2021-01-26 Grigoris Panotopoulos , Angel Rincon , Ilidio Lopes

We calculate quasi-normal f- and g-modes of a neutron star with density discontinuity, which may appear in a phase transition at extreme high density. We find that discontinuity will reflect largely on the f-mode, and that the g-mode could…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Hajime Sotani , Kazuhiro Tominaga , Kei-ichi Maeda

We investigate the photometric variability of magnetized stars, particularly neutron stars, accreting through a magnetic Rayleigh-Taylor-type instability at the disk-magnetosphere interface, and compare it with the variability during stable…

Astrophysics · Physics 2015-05-13 Akshay K. Kulkarni , Marina M. Romanova

We investigate non-axisymmetric low frequency modes of a rotating and magnetized neutron star, assuming that the star is threaded by a dipole magnetic field whose strength at the stellar surface, $B_0$, is less than $\sim 10^{12}$G, and…

Solar and Stellar Astrophysics · Physics 2015-05-14 Umin Lee

We study the secular evolution and gravitational wave signature of a newly-formed, rapidly rotating neutron star. The neutron star may arise from core collapse in a massive star or from the accretion-induced collapse of a white dwarf. After…

Astrophysics · Physics 2009-10-22 Dong Lai , Stu Shapiro

The r-mode instability in rotating relativistic stars has been shown recently to have important astrophysical implications (including the emission of detectable gravitational radiation, the explanation of the initial spins of young neutron…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Nikolaos Stergioulas , Jose A. Font

In the present paper we investigate non-perturbatively and self-consistently the structure of neutron stars in $R$-squared gravity by simultaneously solving the interior and exterior problem. The mass-radius relations are obtained for…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Stoytcho S. Yazadjiev , Daniela D. Doneva , Kostas D. Kokkotas , Kalin V. Staykov

Existing estimates of the gravitational-wave damping timescale of the dominant quadrupole oscillation mode in the case of rapidly rotating stars are based on using a Newtonian estimate for the energy of the mode, in combination with the…

General Relativity and Quantum Cosmology · Physics 2018-01-10 Georgios Lioutas , Nikolaos Stergioulas

In this undergraduate project, f-mode oscillations in neutron stars are used to constrain the equation of state of dense matter. For the first time, a systematic investigation of the role of nuclear saturation parameters on the mode…

High Energy Astrophysical Phenomena · Physics 2021-08-12 Sukrit Jaiswal , Debarati Chatterjee

In this paper for studying the anisotropic strange quark stars, we assume that the radial pressure inside the anisotropic star is a superposition of pressure in an isotropic case plus a Gaussian perturbation term. Considering a…

Solar and Stellar Astrophysics · Physics 2016-07-26 H. Panahi , R. Monadi , I. Eghdami

Context. The seismology of early-type stars is limited by our incomplete understanding of gravito-inertial modes. Aims. We develop a short-wavelength asymptotic analysis for gravito-inertial modes in rotating stars. Methods. The…

Solar and Stellar Astrophysics · Physics 2016-03-02 Vincent Prat , François Lignières , Jérôme Ballot

Neutron Stars are natural laboratories where fundamental properties of matter under extreme conditions can be explored. Modern nuclear physics input as well as many-body theories are valuable tools which may allow us to improve our…

Solar and Stellar Astrophysics · Physics 2015-06-11 V. de la Mota , F. Sébille , Ph. Eudes