The University of Southampton
University of Southampton Institutional Repository

Entropy entrainment and dissipation in finite temperature superfluids

Entropy entrainment and dissipation in finite temperature superfluids
Entropy entrainment and dissipation in finite temperature superfluids
:
Neutron stars are expected to contain several distinct superfluid components, ranging from the neutron superfluid which coexists with the elastic crust to the mixed neutron superfluid/proton superconductor in the outer core and more exotic phases like superfluid hyperons and colour-flavour-locked superconducting quarks in the deep core. These different phases may have significant effect on the dynamics of the system. Building on a general variational framework for multifluid dynamics, we consider the behaviour of superfluid systems at finite temperatures (as required to understand various dissipation channels). As a demonstration of the validity of the underlying principles, such as treating the excitations in the system as a massless "entropy" fluid, we show that the model is formally equivalent to the traditional two-fluid approach for superfluid helium. In particular, we demonstrate how the entropy entrainment is related to the "normal fluid density". We also show how the superfluid constraint of irrotationality reduces the number of dissipation coefficients in the system. The analysis provides insight into the more general problem where vortices are present in the superfluid, and we discuss how the so-called mutual friction force can be accounted for. The end product is a formalism for finite temperature effects in a single condensate that can be applied to both low temperature laboratory systems and the various superfluid phases in a neutron star. This provides a key step towards the modelling of more realistic neutron star dynamics, and the understanding of a range of phenomena from pulsar glitches to magnetar seismology and the gravitational-wave-driven r-mode instability.
superfluids, neutron stars, hydrodynamics, dissipation, thermodynamics
0218-2718
1215-1233
Andersson, Nils
2dd6d1ee-cefd-478a-b1ac-e6feedafe304
Comer, G.L.
f2c1746c-8638-4268-94f0-e5d4375f0358
Andersson, Nils
2dd6d1ee-cefd-478a-b1ac-e6feedafe304
Comer, G.L.
f2c1746c-8638-4268-94f0-e5d4375f0358

Andersson, Nils and Comer, G.L. (2011) Entropy entrainment and dissipation in finite temperature superfluids. International Journal of Modern Physics D, 20 (7), 1215-1233. (doi:10.1142/S0218271811019396).

Record type: Article

Abstract

:
Neutron stars are expected to contain several distinct superfluid components, ranging from the neutron superfluid which coexists with the elastic crust to the mixed neutron superfluid/proton superconductor in the outer core and more exotic phases like superfluid hyperons and colour-flavour-locked superconducting quarks in the deep core. These different phases may have significant effect on the dynamics of the system. Building on a general variational framework for multifluid dynamics, we consider the behaviour of superfluid systems at finite temperatures (as required to understand various dissipation channels). As a demonstration of the validity of the underlying principles, such as treating the excitations in the system as a massless "entropy" fluid, we show that the model is formally equivalent to the traditional two-fluid approach for superfluid helium. In particular, we demonstrate how the entropy entrainment is related to the "normal fluid density". We also show how the superfluid constraint of irrotationality reduces the number of dissipation coefficients in the system. The analysis provides insight into the more general problem where vortices are present in the superfluid, and we discuss how the so-called mutual friction force can be accounted for. The end product is a formalism for finite temperature effects in a single condensate that can be applied to both low temperature laboratory systems and the various superfluid phases in a neutron star. This provides a key step towards the modelling of more realistic neutron star dynamics, and the understanding of a range of phenomena from pulsar glitches to magnetar seismology and the gravitational-wave-driven r-mode instability.

Full text not available from this repository.

More information

Published date: 15 July 2011
Keywords: superfluids, neutron stars, hydrodynamics, dissipation, thermodynamics
Organisations: Applied Mathematics

Identifiers

Local EPrints ID: 337962
URI: https://eprints.soton.ac.uk/id/eprint/337962
ISSN: 0218-2718
PURE UUID: 5ed7fd3f-530d-474d-b870-a8ead4956e2e
ORCID for Nils Andersson: ORCID iD orcid.org/0000-0001-8550-3843

Catalogue record

Date deposited: 08 May 2012 13:24
Last modified: 20 Jul 2019 01:11

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×