Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Negative specific heat in a Lennard-Jones-like gas with long-range
  interactions   We study, through molecular dynamics, a conservative two-dimensional
Lennard-Jones-like gas (with attractive potential $\propto r^{-\alpha}$). We
consider the effect of the range index $\alpha$ of interactions, number of
particles, total energy and particle density. We detect negative specific heat
when the interactions become long-ranged ($0\le \alpha/d<1$).

12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
2
The categories of this paper are: math
9
The categories of this paper are: nlin
19
The categories of this paper are: eess