Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Inverse Beta Decay in a Nonequilibrium Antineutrino Flux from a Nuclear
  Reactor   The evolution of the reactor antineutrino spectrum toward equilibrium above
the inverse beta-decay threshold during the reactor operating period and the
decay of residual antineutrino radiation after reactor shutdown are considered.
It is found that, under certain conditions, these processes can play a
significant role in experiments seeking neutrino oscillations.

5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn