Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Phase space properties of charged fields in theories of local
  observables
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph