Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermodynamics of a quantized electromagnetic field in rectangular
  cavities with perfectly conducting walls   The thermodynamical properties of a quantized electromagnetic field inside a
box with perfectly conducting walls are studied using a regularization scheme
that permits to obtain finite expressions for the thermodynamic potentials. The
source of ultraviolet divergences is directly isolated in the expression for
the density of modes, and the logarithmic infrared divergences are regularized
imposing the uniqueness of vacuum and, consequently, the vanishing of the
entropy in the limit of zero temperature. We thus obtain corrections to the
Casimir energy and pressures, and to the specific heat that are due to
temperature effects; these results suggest effects that could be tested
experimentally.

9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin