Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Rest frame vacuum of the Proca field on the de Sitter expanding universe   The general plane wave solutions of the Proca field in conformal charts of
the de Sitter expanding universe are derived for arbitrary polarizations
showing how the frequencies can be separated in rest frames, defining thus the
rest frame vacuum of this field.

12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci