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Related papers: Spacetime modes of relativistic stars

200 papers

We study oscillations of slowly rotating relativistic barotropic as well as non-barotropic polytropic stars in the Cowling approximation, including first order rotational corrections. By taking into account the coupling between the polar…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Johannes Ruoff , Adamantios Stavridis , Kostas D. Kokkotas

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 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 study the r-modes and rotational ``hybrid'' modes of relativistic stars. As in Newtonian gravity, the spectrum of low-frequency rotational modes is highly sensitive to the stellar equation of state. If the star and its perturbations obey…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Keith H. Lockitch , Nils Andersson , John L. Friedman

Non-radial oscillations of neutron stars provide a powerful probe of stellar structure and relativistic gravity, but a fully general relativistic treatment for gravitationally coupled two-fluid stars with independently conserved currents…

General Relativity and Quantum Cosmology · Physics 2026-05-06 Ankit Kumar , Daniel A. Caballero , Hajime Sotani , Nicolás Yunes

Adopting the Lindblom-Detweiler formalism for polar oscillations of neutron stars, we study the $w$-mode oscillation and find that the Lagrangian change in pressure, measured by the physical quantity $X$, is negligibly small. Based on this…

Astrophysics · Physics 2009-11-13 J. Wu , P. T. Leung

Stellar pulsations in rotating relativistic stars are reviewed. Slow rotation approximation is applied to solving the Einstein equations. The rotational effects on the non-axisymmetric oscillations are explicitly shown in the polar and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yasufumi Kojima

An extensive survey of gravitational-wave modes for uniform density stars is presented. The study covers stars ranging in compactness from $R/M=100$ to the limit of stability in general relativity: $R/M = 9/4$. We establish that polar and…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Nils Andersson , Yasufumi Kojima , Kostas D. Kokkotas

We consider the perturbations of a relativistic star as an initial-value problem. Having discussed the formulation of the problem (the perturbation equations and the appropriate boundary conditions at the centre and the surface of the star)…

General Relativity and Quantum Cosmology · Physics 2016-08-25 Gabrielle Allen , Nils Andersson , Kostas D. Kokkotas , Bernard F. Schutz

A new method is presented here for evaluating approximately the pulsation modes of relativistic stellar models. This approximation relies on the fact that gravitational radiation influences these modes only on timescales that are much…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Lee Lindblom , Gregory Mendell , James R. Ipser

In polar oscillations of compact stars dynamical changes in spacetime and matter are in general coupled together. Based on the theory of stellar pulsation proposed by Allen et al. [Phys. Rev. D 58, 124012 (1998)], we establish a feasible…

General Relativity and Quantum Cosmology · Physics 2013-12-18 Y. J. Zhang , Q. Q. Zhu , J. Wu , P. T. Leung

The first numerical study of axial (toroidal) pulsation modes of a slowly rotating relativistic star is presented. The calculation includes terms of first order in $\epsilon \equiv \Omega \sqrt{R^3/M}<<1$ ($R$ is the radius, $M$ is the mass…

General Relativity and Quantum Cosmology · Physics 2009-07-09 Nils Andersson

We present the results of a numerical study of the fluid $f$, $p$ and the gravitational $w$ modes for increasingly relativistic nonrotating polytropes. The results for $f$ and $w$-modes are in good agreement with previous data for uniform…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Nils Andersson , Kostas D. Kokkotas

Peculiar A stars are so named because they exhibit abundance peculiarities in their atmospheres. It is believed that these arise as a result of differentiation of chemical species in large magnetic spots in which convective mixing is…

Solar and Stellar Astrophysics · Physics 2011-12-06 Douglas Gough

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

Perturbations of rotating relativistic stars can be classified by their behavior under parity. For axial perturbations (r-modes), initial data with negative canonical energy is found with angular dependence $e^{im\phi}$ for all values of…

General Relativity and Quantum Cosmology · Physics 2009-10-30 John L. Friedman , Sharon M. Morsink

In this paper we review the recent developments in the relativistic theory of stellar pulsations with special emphasis on the spacetime or w-modes. We discuss also the excitation of these modes and the information about the neutron star…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Kostas D. Kokkotas

We present new numerical algorithms for the coupled Einstein-perfect fluid system in axisymmetry. Our framework uses a foliation based on a family of light cones, emanating from a regular center, and terminating at future null infinity.…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Florian Siebel , Jose A. Font , Ewald Mueller , Philippos Papadopoulos

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

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
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