Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hydromagnetic waves in a superfluid neutron star with strong vortex
  pinning   Neutron-star cores may be hosts of a unique mixture of a neutron superfluid
and a proton superconductor. Compelling theoretical arguments have been
presented over the years that if the proton superconductor is of type II, than
the superconductor fluxtubes and superfluid vortices should be strongly coupled
and hence the vortices should be pinned to the proton-electron plasma in the
core. We explore the effect of this pinning on the hydromagnetic waves in the
core, and discuss 2 astrophysical applications of our results: 1. We show that
even in the case of strong pinning, the core Alfven waves thought to be
responsible for the low-frequency magnetar quasi-periodic oscillations (QPO)
are not significantly mass-loaded by the neutrons. The decoupling of about 0.95
of the core mass from the Alfven waves is in fact required in order to explain
the QPO frequencies, for simple magnetic geometries and for magnetic fields not
greater than 10^{15} Gauss. 2. We show that in the case of strong vortex
pinning, hydromagnetic stresses exert stabilizing influence on the Glaberson
instability, which has recently been proposed as a potential source of
superfluid turbulence in neutron stars.

36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int