Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The same physics underlying SGRs, AXPs, and radio pulsars   Unexpected sign, significant magnitude and time-variation of frequency second
derivative exist not only in singular radio pulsars but also in Soft Gamma
repeaters (SGRs) and Anomalous X-ray pulsars (AXPs). This paper shows that the
these phenomena are related, and can be interpreted by a simple unified model,
long-term orbital effect. Thus many of previous ``isolated'' pulsars may be
binary pulsars, i.e., orbital period
  $P_b\approx(47, 72)$min for AXP 1E 2259+586, and $P_b\approx (20, 34)$min for
PSR J1614-5047, $P_b\approx (3.6, 6.4)$min for SGR 1900+14, and $P_b\approx
(1.5, 5.8)$min for SGR 1806-20. In addition to X-ray pulsar, 1E 1207.4-5209,
these two SGRs may be the new ultra-compact binary pulsars with orbital period
of a few minutes. There might be more binary pulsars that suitable for
gravitational wave detection than we had thought.

15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc