Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetar Crusts: Matter at $10^{15}$ Gauss   In this work we find that the at the high polar magnetic fields of magnetars,
$B \sim 10^{14-15}$ G, the outermost crust ($\rho < 10^7$ gm/cc) of the star
can become a transverse insulator and a filamentary crystal along the field
direction. Also, the transverse conductivity in the crust goes inversely as the
square of polar magnetic field (as $1/B^2$). At these high fields the
transverse crustal currents associated with the polar magnetic field can then
dissipate more effectively via Ohm's law.

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The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
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The categories of this paper are: hep-th
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The categories of this paper are: stat
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org