Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Particle propagation in cosmological backgrounds   We study the quantum propagation of particles in cosmological backgrounds, by
considering a doublet of massive scalar fields propagating in an expanding
universe, possibly filled with radiation. We focus on the dissipative effects
related to the expansion rate. At first order, we recover the expected result
that the decay rate is determined by the local temperature. Beyond linear
order, the decay rate has an additional contribution governed by the expansion
parameter. This latter contribution is present even for stable particles in the
vacuum. Finally, we analyze the long time behaviour of the propagator and
briefly discuss applications to the trans-Planckian question.

32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat