Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Model to Study Finite-Size and Magnetic Effects on the Phase
  Transition of a Fermion Interacting System   We present a model to study effects from an external magnetic field, chemical
potential, and finite size, on the phase structure of a massive four- and
six-fermion interacting system. These effects are introduced by a method of
compactification of coordinates, a generalization of the standard Matsubara
prescription. Through the compactification of the $z$ coordinate and of
imaginary time, we describe a heated system with the shape of a film of
thickness $L$, at temperature $\beta^{-1}$ undergoing first- or second-order
phase transition. We have found a strong dependence of the temperature
transition on the constants couplings $\lambda$ and $\eta$. Besides magnetic
catalysis and symmetry breaking for both kinds of transition, we have found an
inverse symmetry breaking phenomenon with respect to first-order phase
transition.

17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci