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Related papers: Slowly Rotating Two-Fluid Neutron Star Model

200 papers

We revisit the problem of inertial r-modes in stratified stars, drawing on a more precise description of the composition stratification in a mature neutron star. The results highlight issues with the traditional approach to the problem,…

General Relativity and Quantum Cosmology · Physics 2023-05-23 Nils Andersson , Fabian Gittins

We study time evolutions of superfluid neutron stars, focussing on the nature of the oscillation spectrum, the effect of mutual friction force on the oscillations and the hydrodynamical spin-up phase of pulsar glitches. We linearise the…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. Passamonti , N. Andersson

The present paper is devoted to a study of the equilibrium configurations of slowly rotating anisotropic stars in the framework of general relativity. For that purpose, we provide the equations of structure where the rotation is treated to…

General Relativity and Quantum Cosmology · Physics 2024-07-23 Philip Beltracchi , Camilo Posada

We develop a Lagrangian perturbation framework for rotating non-relativistic superfluid neutron stars. This leads to the first generalization of classic work on the stability properties of rotating stars to models which account for the…

Astrophysics · Physics 2009-11-10 N. Andersson , G. L. Comer , K. Grosart

The r-modes of neutron stars can be driven unstable by gravitational radiation. While linear perturbation theory predicts the existence of this instability, linear theory can't provide any information about the nonlinear development of the…

Astrophysics · Physics 2009-11-07 Sharon M. Morsink

We perform a detailed analysis of radial oscillations to discuss dynamical stability in two-fluid neutron stars composed of ordinary nuclear matter and a gravitationally coupled dark matter component. Using a fully relativistic two-fluid…

High Energy Astrophysical Phenomena · Physics 2025-09-05 Ankit Kumar , Hajime Sotani

We discuss short wavelength (inertial wave) instabilities present in the standard two-fluid neutron star model when there is sufficient relative flow along the superfluid neutron vortex array. We demonstrate that these instabilities may be…

Astrophysics · Physics 2009-11-13 K. Glampedakis , N. Andersson , D. I. Jones

Despite the recent excitement over the r-mode instability of rotating stars, these modes are not yet well-understood for stellar models appropriate to neutron stars - perfect fluid models in which both the equilibrium and perturbed…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Keith H. Lockitch

Magnetic field evolution in neutron star cores is not fully understood. We describe the field evolution both for one barotropic fluid as well as two collisionally coupled barotropic fluids with different density profiles using the anelastic…

High Energy Astrophysical Phenomena · Physics 2025-12-16 Andrei Igoshev , Nicolás A. Moraga , Andreas Reisenegger , Calum S. Skene , Rainer Hollerbach

We study nonaxisymmetric perturbations of rotating relativistic stars. modeled as perfect-fluid equilibria. Instability to a mode with angular dependence $\exp(im\phi)$ sets in when the frequency of the mode vanishes. The locations of these…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Nikolaos Stergioulas , John L. Friedman

It is shown how to set up a mathematically elegant and fully relativistic superfluid model that can provide a realistic approximation (neglecting small anisotropies due to crust solidity, magnetic fields, et cetera, but allowing for the…

Astrophysics · Physics 2009-10-30 David Langlois , David M. Sedrakian , Brandon Carter

When a rotating neutron star loses angular momentum, the reduction of the centrifugal force makes it contract. This perturbs each fluid element, raising the local pressure and originating deviations from beta equilibrium, inducing reactions…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Nicolás González-Jiménez , Cristóbal Petrovich , Andreas Reisenegger

In this paper we have examined numerically exact configurations of close binary systems composed of incompressible fluids with internal flows. Component stars of binary systems are assumed to be circularly orbiting each other but rotating…

Astrophysics · Physics 2009-10-30 Koji Uryu , Yoshiharu Eriguchi

This article starts by providing an introductory overview of the theoretical mechanics of rotating neutron stars as developped to account for the frequency variations, and particularly the discontinuous glitches, observed in pulsars. The…

Astrophysics · Physics 2007-05-23 Brandon Carter

We investigate the oscillations of slowly rotating superfluid stars, taking into account the vortex mediated mutual friction force that is expected to be the main damping mechanism in mature neutron star cores. Working to linear order in…

Astrophysics · Physics 2009-07-30 N. Andersson , K. Glampedakis , B. Haskell

We consider both mode calculations and time evolutions of axial r-modes for relativistic uniformly rotating non-barotropic neutron stars, using the slow-rotation formalism, in which rotational corrections are considered up to linear order…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Johannes Ruoff , Kostas D. Kokkotas

We consider the evolution in full general relativity of a family of linearly unstable isolated spherical neutron stars under the effects of very small, perturbations as induced by the truncation error. Using a simple ideal-fluid equation of…

General Relativity and Quantum Cosmology · Physics 2011-07-18 David Radice , Luciano Rezzolla , Thorsten Kellermann

We study the tidal problem and the resulting $I$-Love-$Q$ approximate universal relations for rotating superfluid neutron stars in the Hartle-Thorne formalism. Superfluid stars are described in this work by means of a two-fluid model…

General Relativity and Quantum Cosmology · Physics 2023-11-23 Eneko Aranguren , José A. Font , Nicolas Sanchis-Gual , Raül Vera

Superfluid hydrodynamics affects the spin-evolution of mature neutron stars, and may be key to explaining timing irregularities such as pulsar glitches. However, most models for this phenomenon exclude the global instability required to…

Solar and Stellar Astrophysics · Physics 2013-03-27 N. Andersson , K. Glampedakis , M. Hogg

In the present article we have obtained new set of exact solutions of Einstein field equations for anisotropic fluid spheres by using the Herrera et al.[1] algorithm. The anisotropic fluid solution so obtained join continuously to…

General Relativity and Quantum Cosmology · Physics 2015-09-30 S. K. Maurya , Y. K. Gupta , M. K. Jasim