Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Baryogenesis from a Lepton Asymmetric Universe   We demonstrate that $CP-$violation in the Majorana mass matrices of the heavy
neutrinos can generate a $CP-$asymmetric universe. The subsequent decay of the
Majorana particles generates a lepton number asymmetry. During the electroweak
phase transition the lepton asymmetry is converted into a baryon asymmetry,
which survives down to this time.

32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex