Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Soft gamma repeaters activity in time   In this short note I discuss the hypothesis that bursting activity of
magnetars evolves in time analogously to the glitching activity of normal radio
pulsars (i.e. sources are more active at smaller ages), and that the increase
of the burst rate follows one of the laws established for glitching radio
pulsars. If the activity of soft gamma repeaters decreases in time in the way
similar to the evolution of core-quake glitches ($\propto t^{5/2}$), then it is
more probable to find the youngest soft gamma repeaters, but the energy of
giant flares from these sources should be smaller than observed $10^{44}$
--$10^{46}$ ergs as the total energy stored in a magnetar's magnetic field is
not enough to support thousands of bursts similar to the prototype 5 March 1979
flare.

18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio