Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The maximum dipole moments of neutron stars implied by the
  Barrow-Gibbons conjecture   The maximum magnetic moment to angular momentum conjecture, recently posed by
Barrow \& Gibbons, is in tension with the generally accepted parameters of
magnetars. According to the conjecture the dimensionless
Schuster-Wilson-Blacket number, $c\mu/J\sqrt{G}$ where $\mu$ is the magnetic
moment and $J$ is the angular momentum, should be of order unity. A resolution
is to assume that not only the low-magnetic field magnetars, but all magnetars
have their super-critical fields in the higher multipoles. This requires the
presence of external torques other than the magnetic dipole torque, such as
from fallback disks or winds, on these systems to yield the measured high
spin-down rates.

30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs