Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effective Potential at Finite Temperature: RG improvement vs. High
  temperature expansion   We have applied the recently proposed renormalization group improvement
procedure of the finite temperature effective potential, and have investigated
extensively the phase structure of the massive scalar $\phi^4$ model, showing
that the $\phi^4$ model has a rich 3-phase structure at $T \neq 0$, two of them
are not seen in the ordinary perturbative analysis. Temperature dependent phase
transition in this model is shown to be strongly the first order.

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The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
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
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The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas