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200 papers

Asteroseismology, the study of stellar vibration, has met with great success, shedding light on stellar interior structure, rotation, and magnetism. Prominently known as $\delta$ Scutis, intermediate-mass main-sequence oscillators that…

Solar and Stellar Astrophysics · Physics 2024-10-01 Subrata Kumar Panda , Shravan Hanasoge , Siddharth Dhanpal , Vageesh D. C

The oscillation modes of stars play an important role in observations, and on the understanding of stellar stability properties. The role of viscosity in the oscillation modes of compact stars has been so far understood very loosely only,…

General Relativity and Quantum Cosmology · Physics 2026-04-16 Sofía Bussières , Jaime Redondo-Yuste , José Javier Ortega Gómez , Vitor Cardoso

We use perturbation theory and the relativistic Cowling approximation to numerically compute characteristic oscillation modes of rapidly rotating relativistic stars which consist of a perfect fluid obeying a polytropic equation of state. We…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Stratos Boutloukos , Hans-Peter Nollert

We investigate the effect of a magnetic field on the global oscillation modes of a rotating fluid star in the magnetohydrodynamic approximation. We present general equations for the modification of any type of fluid mode due to a general…

Astrophysics · Physics 2009-11-07 Sharon M. Morsink , Vahid Rezania

Using time evolutions of the relevant linearised equations we study non-axisymmetric oscillations of rapidly rotating and superfluid neutron stars. We consider perturbations of Newtonian axisymmetric background configurations and account…

Astrophysics · Physics 2009-11-13 Andrea Passamonti , Brynmor Haskell , Nils Andersson

We review the derivation of the pulsations equations for spherically symmetric boson stars and then make a thorough study of the radial oscillation frequencies for the fundamental and first excited modes. We do this for self-interacting…

General Relativity and Quantum Cosmology · Physics 2021-06-16 Ben Kain

The effects of nonlinear oscillations in compact stars are attracting considerable current interest. In order to study such phenomena in the framework of fully nonlinear general relativity, highly accurate numerical studies are required. We…

General Relativity and Quantum Cosmology · Physics 2009-09-24 Michael Gabler , Ulrich Sperhake , Nils Andersson

p-mode oscillations in solar-like stars are excited by the outer convection zone in these stars and reflected close to the surface. The p-modes are trapped inside an acoustic cavity, but the modes only stay trapped up to a given frequency…

Astrophysics · Physics 2009-11-13 C. Karoff

Context: Mode identification is a crucial step to comparing observed frequencies with theoretical ones, but has proven to be difficult in rapidly rotating stars. Aims: To further constrain mode identification, we aim to accurately calculate…

Solar and Stellar Astrophysics · Physics 2015-06-12 D. R. Reese , V. Prat , C. Barban , C. van 't Veer-Menneret , K. B. MacGregor

We model the stochastic excitation of acoustic modes in solar-like pulsators taking into account the action of differential rotation. We derive the theoretical formalism for the stochastic excitation with differential rotation and make use…

Solar and Stellar Astrophysics · Physics 2024-10-31 Gabriel Biscarrat , Leïla Bessila , Stéphane Mathis

We compute the lowest frequency non-radial oscillation modes of dilute axion stars. The effective potential that enters into the Schr{\"o}dinger-like equation, several associated eigenfunctions, and the large as well as the small frequency…

General Relativity and Quantum Cosmology · Physics 2019-07-24 Grigoris Panotopoulos , Ilídio Lopes

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 evaluate the impact of the rotation on the stochastic excitation of acoustic (p) modes in solar-like pulsators. First, we derive the forced wave equation taking rotation into account and we compute the source terms, which inject energy…

Solar and Stellar Astrophysics · Physics 2024-10-31 Leïla Bessila , Adrien Deckx Van Ruys , Valentin Buriasco , Stéphane Mathis , Lisa Bugnet , Rafael A. García , Savita Mathur

Context. Recently our ability to study stars using asteroseismic techniques has increased dramatically, largely through the use of space based photometric observations. Work has also been done using ground based spectroscopic observations…

Solar and Stellar Astrophysics · Physics 2018-10-03 Jesper Schou

In this review article, we present the main results from our most recent research concerning the oscillations of fast rotating neutron stars. We derive a set of time evolution equations for the investigation of non-axisymmetric oscillations…

General Relativity and Quantum Cosmology · Physics 2021-10-04 Christian J. Krüger , Kostas D. Kokkotas , Praveen Manoharan , Sebastian H. Völkel

In the era of gravitational wave astronomy, radial oscillations hold significant potential for not only uncovering the microphysics behind the internal structure but also investigating the stability of neutron stars (NSs). We start by…

Nuclear Theory · Physics 2026-02-02 Sayantan Ghosh , Sailesh Ranjan Mohanty , Tianqi Zhao , Bharat Kumar

While many intermediate- and high-mass main sequence stars are rapidly and differentially rotating, the effects of rotation on oscillation modes are poorly known. In this communication we present a first study of axisymmetric…

Solar and Stellar Astrophysics · Physics 2014-11-14 Giovanni M. Mirouh , Clément Baruteau , Michel Rieutord , Jérôme Ballot

Nonlinear growth of the bar-mode deformation is studied for a differentially rotating star with supercritical rotational energy. In particular, the growth mechanism of some azimuthal modes with odd wave numbers is examined by comparing a…

Astrophysics · Physics 2008-12-17 Yasufumi Kojima , Motoyuki Saijo

Using weakly non-linear theory of oscillation, we estimate the amplitudes of low frequency modes in a slowly pulsating B (SPB) star, taking account of the effects of rotation on the modes. Applying the formulation by Schenk et al (2002), we…

Solar and Stellar Astrophysics · Physics 2015-06-03 Umin Lee

When a relativistic star rotates slowly and rigidly, centrifugal forces flatten it slightly, thereby catalyzing a small admixture of quadrupolar vibration into its radial modes and a damping of the resulting quasi-radial modes. The damping…

General Relativity and Quantum Cosmology · Physics 2025-09-09 James B. Hartle , Kip S. Thorne