Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Particle Production from Geometric Transition in Expanding Universe   The geometric transitions from the evolution in the complex plane of time
provide channels for particle production for a quantum field in expanding
universes. The production rate for one pair is obtained by squaring and summing
the scattering matrix between the in-vacuum and the transported one over all
possible independent closed paths of winding number 1.

19
The categories of this paper are: eess
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org