Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Tit for Tat: Cooperation, communication, and how each could stabilize
  the other
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an