Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Introduction to leptogenesis
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom