Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Diffusion of a massive quantum particle coupled to a quasi-free thermal
  medium   We consider a heavy quantum particle with an internal degree of freedom
moving on the $d$-dimensional lattice $\bbZ^d$ (e.g., a heavy atom with
finitely many excited states). The particle is coupled to a thermal medium
(bath) consisting of free relativistic bosons through an interaction of
strength $\la$ linear in creation and annihilation operators. The mass of the
quantum particle is assumed to be of order $\la^{-2}$, and we assume that the
internal degree of freedom is coupled "effectively" to the thermal medium. We
prove that the motion of the quantum particle is diffusive in $d\geq 4$ and for
$\la$ small enough.

33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
3
The categories of this paper are: physics