English
Related papers

Related papers: Fast Rotating Relativistic Stars: Spectra and Stab…

200 papers

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 present paper we examine gravitational wave asteroseismology relations for f-modes of rapidly rotating neutron stars. An approach different to the previous studies is employed - first, the moment of inertia is used instead of the…

Solar and Stellar Astrophysics · Physics 2015-12-09 Daniela D. Doneva , Kostas D. Kokkotas

Rotating relativistic stars are receiving significant attention in recent years, because of the information they can yield about the equation of state of matter at extremely high densities and because they are one of the more possible…

General Relativity and Quantum Cosmology · Physics 2016-10-19 Nikolaos Stergioulas

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

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

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

We use time-evolutions of the linear perturbation equations to study the oscillations of rapidly rotating neutrons stars. Our models account for the buoyancy due to composition gradients and we study, for the first time, the nature of the…

Astrophysics · Physics 2009-11-13 A. Passamonti , B. Haskell , N. Andersson , D. I. Jones , I. Hawke

Rapidly rotating neutron stars can be unstable to the gravitational-wave-driven CFS mechanism if they have a neutral point in the spectrum of nonaxisymmetric f-modes. We investigate the frequencies of these modes in two sequences of…

Solar and Stellar Astrophysics · Physics 2010-11-16 Burkhard Zink , Oleg Korobkin , Erik Schnetter , Nikolaos Stergioulas

We present a new survey of the radial oscillation modes of neutron stars. This study complements and corrects earlier studies of radial oscillations. We present an extensive list of frequencies for the most common equations of state and…

General Relativity and Quantum Cosmology · Physics 2011-05-23 Kostas. D. Kokkotas , Johannes Ruoff

We study the effects of rotation on the torsional modes of oscillating relativistic stars with a solid crust. Earlier works in Newtonian theory provided estimates of the rotational corrections for the torsional modes and suggested that they…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. Vavoulidis , A. Stavridis , K. D. Kokkotas , H. Beyer

We perform the first study of the oscillation frequencies of rapidly rotating neutron stars in alternative theories of gravity, focusing mainly on the fundamental $f$-modes. We concentrated on a particular class of alternative theories -…

General Relativity and Quantum Cosmology · Physics 2017-09-13 Stoytcho S. Yazadjiev , Daniela D. Doneva , Kostas D. Kokkotas

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

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

The present work investigates the numerical evolution of linearized oscillations of non-rotating, spherically symmetric neutron stars within the framework of general relativity. We derive the appropriate equations using the (3+1)-formalism.…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Johannes Ruoff

Recent developments on the rotational instabilities of relativistic stars are reviewed. The article provides an account of the theory of stellar instabilities with emphasis on the rotational ones. Special attention is being paid to the…

General Relativity and Quantum Cosmology · Physics 2017-08-23 K. D. Kokkotas , J. Ruoff

Scalar-tensor theories are well studied extensions of general relativity that offer deviations which are yet within observational boundaries. We present the time evolution equations governing the perturbations of a nonrotating scalarized…

General Relativity and Quantum Cosmology · Physics 2021-07-06 Christian J. Krüger , Daniela D. Doneva

$f(R)$ theories of gravity are one of the most popular alternative explanations for dark energy and therefore studying the possible astrophysical implications of these theories is an important task. In the present paper we make a…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Stoytcho S. Yazadjiev , Daniela D. Doneva , Kostas D. Kokkotas

In this short review we discuss the relevance of ongoing research into stellar oscillations and associated instabilities for the detection of gravitational waves and the future field of ``gravitational-wave astronomy''.

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

We provide a summary of several parametrisations for the nuclear equation of state that have been proposed over the past decades and list viable ranges for their parameters. Based on these parametrisations, we construct a large database of…

General Relativity and Quantum Cosmology · Physics 2025-11-27 Christian J. Krüger , Mariachiara Celato

We study the oscillations of neutron and strange stars in $R^2$ gravity. More precisely the nonradial $f$-modes are examined and the differences with pure general relativity are investigated. Using these results we build several…

General Relativity and Quantum Cosmology · Physics 2015-09-23 Kalin V. Staykov , Daniela D. Doneva , Stoytcho S. Yazadjiev , Kostas D. Kokkotas
‹ Prev 1 2 3 10 Next ›