Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Functional approach to quantum friction: effective action and
  dissipative force   We study the Casimir friction due to the relative, uniform, lateral motion of
two parallel semitransparent mirrors coupled to a vacuum real scalar field,
$\phi$. We follow a functional approach, whereby nonlocal terms in the action
for $\phi$, concentrated on the mirrors' locii, appear after functional
integration of the microscopic degrees of freedom. This action for $\phi$,
which incorporates the relevant properties of the mirrors, is then used as the
starting point for two complementary evaluations: Firstly, we calculate the {
in-out} effective action for the system, which develops an imaginary part,
hence a non-vanishing probability for the decay (because of friction) of the
initial vacuum state. Secondly, we evaluate another observable: the vacuum
expectation value of the frictional force, using the { in-in} or Closed Time
Path formalism. Explicit results are presented for zero-width mirrors and
half-spaces, in a model where the microscopic degrees of freedom at the mirrors
are a set of identical quantum harmonic oscillators, linearly coupled to $\phi$

2
The categories of this paper are: math
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg