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Related papers: Alfv\'en Polar Oscillations of Relativistic Stars

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A linear response relation between metric and fluid perturbations driven by a background noise source is used as a framework for obtaining non-radial polar perturbations in dense matter relativistic stars. The perturbations carry a…

General Relativity and Quantum Cosmology · Physics 2023-06-16 Seema Satin

In this work, we have studied oscillations in the crust of a neutron star which magnetic field has both dipolar and toroidal components, the former extends from the stellar interior to the outer space and the later is confined inside the…

General Relativity and Quantum Cosmology · Physics 2020-02-05 Gibran Henrique de Souza , Ernesto Kemp

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

Stars are not perfectly spherically symmetric. They are deformed by rotation and magnetic fields. Until now, the study of stellar shapes has only been possible with optical interferometry for a few of the fastest-rotating nearby stars. We…

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 present a numerical approach to investigate the relationship between magnetic fields and Faraday rotation effects in clusters of galaxies. We can infer the structure and strength of intra-cluster magnetic fields by comparing our…

Astrophysics · Physics 2009-11-10 M. Murgia , F. Govoni , L. Feretti , G. Giovannini , D. Dallacasa , R. Fanti , G. B. Taylor , K. Dolag

Aims: This paper extends previous studies in modeling time varying linear polarization due to axisymmetric magnetic fields in rotating stars. We use the Hanle effect to predict variations in net line polarization, and use geometric…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 R. Ignace , K. T. Hole , J. P. Cassinelli , G. D. Henson

Neutron stars are the most compact horizonless objects in the Universe, exhibiting the strongest known magnetic fields. They are potential sources of coincident gravitational waves and electromagnetic radiation across the entire spectrum.…

High Energy Astrophysical Phenomena · Physics 2025-08-29 Fabrizio Venturi Piñas , Anson Ka Long Yip , Patrick Chi-Kit Cheong , Milton Ruiz

We consider torsional Alfv\'en waves which may be excited in Jupiter's metallic hydrogen region. These axisymmetric zonal flow fluctuations have previously been examined for incompressible fluids in the context of Earth's liquid iron core.…

Earth and Planetary Astrophysics · Physics 2019-05-29 Kumiko Hori , Robert J. Teed , Chris A Jones

The evolution and viscous damping of cosmic magnetic fields in the early universe, is analysed. Using the fact that the fluid, electromagnetic, and shear viscous energy-momentum tensors are all conformally invariant, the evolution is…

Astrophysics · Physics 2011-09-29 Kandaswamy Subramanian , John D. Barrow

Quasi-toroidal oscillations in slowly rotating stars are examined in the framework of general relativity. The oscillation frequency to first order of the rotation rate is not a single value even for uniform rotation unlike the Newtonian…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Yasufumi Kojima

Context. The dipole modes are the most common geometry of oscillations in roAp stars inferred from photometric measurements and are therefore of special interest for asteroseismic purposes. Aims. We present a theoretical and analytical…

Solar and Stellar Astrophysics · Physics 2011-10-06 L. Bigot , D. W. Kurtz

Oscillations between photons and axion-like particles (ALP) travelling in intergalactic magnetic fields have been invoked to explain a number of astrophysical phenomena, or used to constrain ALP properties using observations. One example is…

High Energy Astrophysical Phenomena · Physics 2016-06-15 Chen Wang , Dong Lai

With the Cowling approximation, the torsional oscillations on relativistic stars in tensor-vector-scalar (TeVeS) theory are examined. The spectrum features in TeVeS are very similar to those in general relativity (GR), but the torsional…

High Energy Astrophysical Phenomena · Physics 2011-07-05 Hajime Sotani

Rapidly rotating stars show short-period oscillations in magnetic activity and polar appearance of starspots. The aim of this paper is to study large-scale shallow water waves in the tachoclines of rapidly rotating stars and their…

Solar and Stellar Astrophysics · Physics 2015-05-28 T. V. Zaqarashvili , R. Oliver , J. L. Ballester , M. Carbonell , M. L. Khodachenko , H. Lammer , M. Leitzinger , P. Odert

MHD turbulence driven at velocities higher than the Alfv\'en velocity, i.e., super-Alfv\'enic turbulence, is widely spread in astrophysical environments, including galaxy clusters and molecular clouds. For statistical studies of such…

Astrophysics of Galaxies · Physics 2025-11-13 A. Lazarian , D. Pogosyan , Y. Hu

We present a solitary Alfv\'en wave model that exhibits nontrivial three-dimensional twisting of open magnetic field lines while preserving constant $|B|$. Embedded rotational discontinuities sharply deflect the otherwise uniform field…

Space Physics · Physics 2025-12-16 Zesen Huang , Marco Velli , Yuliang Ding

We have developed a formalism to study non-adiabatic, non-radial oscillations of non-rotating compact stars in the frequency domain, including the effects of thermal diffusion in the framework of general relativistic perturbation theory.…

General Relativity and Quantum Cosmology · Physics 2009-11-10 L. Gualtieri , J. A. Pons , G. Miniutti

We investigate nonradial $f$-mode oscillations of protoneutron stars in full general relativity, employing equations of state described by the Brueckner-Hartree-Fock theory or the relativistic mean field model, while assuming isentropy and…

High Energy Astrophysical Phenomena · Physics 2025-12-04 Zi-Yue Zheng , Ting-Ting Sun , Huan Chen , Jin-Biao Wei , Xiao-Ping Zheng , G. F. Burgio , H. -J. Schulze

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