Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic helicity evolution in a neutron star accounting for the
  Adler-Bell-Jackiw anomaly   We analyze the role of the surface terms in the conservation law for the sum
of the magnetic helicity density and the chiral imbalance of the charged
particle densities. These terms are neglected in the Anomalous
MagnetoHydroDynamics (AMHD), where infinite volume is considered typically. We
discuss a finite volume system, such as a magnetized neutron star (NS), and
study the contribution of the surface terms to the evolution of the magnetic
helicity. Accounting for the fast washing out of the chiral imbalance in a
nascent NS, we demonstrate that the surface terms contribution can potentially
lead to the reconnection of magnetic field lines and subsequent gamma or X-ray
bursts observed from magnetars. We derive the additional surface terms
originated by the mean spin flux through a volume boundary arising due to
macroscopic spin effects in electron-positron plasma. Then, comparing this
quantum surface term with the classical one known in standard MHD, we find that
the new quantum contribution prevails over classical term for the rigid NS
rotation only.

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The categories of this paper are: physics
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
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The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
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The categories of this paper are: supr-con
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat