Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Origin of sources of repeating fast radio bursts with periodicity in
  close binary systems   It is proposed that sources of repeating fast radio bursts with detected
periodicity are magnetars with extremely short initial spin periods at the
protoneutron star stage, formed in binaries after tidal synchronization of
their progenitor cores on late stages of thermonuclear burning in very close
systems with orbital periods about a few days. This formation channel is in
several respects different from evolution of progenitors of normal magnetars,
and thus, it explains some differences between repeating and non-repeating
sources of FRBs.

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The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess