Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The evolution of core and surface magnetic field in isolated neutron
  stars   We apply the model of flux expulsion from the superfluid and superconductive
core of a neutron star, developed by Konenkov & Geppert (2000), both to neutron
star models based on different equations of state and to different initial
magnetic field structures. When initially the core and the surface magnetic
field are of the same order of magnitude, the rate of flux expulsion from the
core is almost independent of the equation of state, and the evolution of the
surface field decouples from the core field evolution with increasing
stiffness. When the surface field is initially much stronger than the core
field, the magnetic and rotational evolution resembles to those of a neutron
star with a purely crustal field configuration; the only difference is the
occurence of a residual field. In case of an initially submerged field
significant differences from the standard evolution occur only during the early
period of neutron star's life, until the field has been rediffused to the
surface. The reminder of the episode of submergence is a correlation of the
residual field strength with the submergence depth of the initial field. We
discuss the effect of the rediffusion of the magnetic field on to the
difference between the real and the active age of young pulsars and on their
braking indices. Finally, we estimate the shear stresses built up by the moving
fluxoids at the crust--core interface and show that preferentially in neutron
stars with a soft equation of state these stresses may cause crust cracking.

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The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
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The categories of this paper are: chem-ph
2
The categories of this paper are: math
1
The categories of this paper are: cs
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
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The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
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The categories of this paper are: eess
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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th
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The categories of this paper are: funct-an