Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Vacuum effects in electrodynamics and in Yang-Mills theory in (2+1)
  dimensions   Vacuum effects in (2+1)-dimensional quantum electrodynamics (QED) with the
topological Chern-Simons term are considered. The photon polarization operator
is studied and the decay rate for the electron-positron photoproduction is
presented as a function of the photon energy and external field strength. The
radiatively induced electron mass shift in an external magnetic field is
investigated. The electron self-energy in topologically massive (2+1)-QED at
finite temperature and density is studied. The parity breaking part of the
Yang-Mills action in the framework of the $SU(2)\times U(1)$ gauge field model
at finite temperature is considered.

37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph