Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonequilibrium quantum dynamics of phase transitions in an expanding
  universe   I summarize the derivation of a set of Feynman rules appropriate for the
perturbative description of the nonequilibrium dynamics of the
symmetry-breaking phase transition in $\lambda\phi^4$ theory in a
Robertson-Walker universe. The approximation scheme I develop provides for a
treatment of dissipative effects which are essential to an adequate description
of the nonequilibrium state. It also provides for the emergence from an
initially symmetric state of a final state exhibiting the properties of
spontaneous symmetry breaking without the introduction by hand of any explicit
symmetry breaking.

26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg