Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Casimir-Lifshitz force out of thermal equilibrium and asymptotic
  non-additivity   We investigate the force acting between two parallel plates held at different
temperatures. The force reproduces, as limiting cases, the well known
Casimir-Lifshitz surface-surface force at thermal equilibrium and the
surface-atom force out of thermal equilibrium recently derived by M. Antezza
\emph{et al.}, Phys. Rev. Lett. {\bf 95}, 113202 (2005). The asymptotic
behavior of the force at large distances is explicitly discussed. In particular
when one of the two bodies is a rarefied gas the force is not additive, being
proportional to the square root of the density. Nontrivial cross-over regions
at large distances are also identified.

24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph