Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Scalar Field Theory at Finite Temperature in D=2+1   We discuss the $\phi^6 $ theory defined in $D=2+1$-dimensional space-time and
assume that the system is in equilibrium with a thermal bath at temperature
$\beta^{-1}$. We use the $ 1/N $ expansion and the method of the composite
operator (CJT) for summing a large set of Feynman graphs.We demonstrate
explicitly the Coleman-Mermin-Wagner theorem at finite temperature.

21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an