Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The CPT theorem   We provide a rigorous proof of the CPT theorem within the framework of
'Lagrangian' quantum field theory. This is in contrast to the usual rigorous
proofs in purely axiomatic frameworks, and non-rigorous proof-sketches within
the Lagrangian framework.

23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph