Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dirac Sea for Bosons II -- Study of the Naive Vacuum Theory for the
  Playground World Prior to Filling the Negative Energy Sea --   We use our previous idea, in which at first we perform a naive second
quantization of both negative and positive energy for the Klein-Gordon equation
analogous to the unfilled Dirac sea for fermions, to study as a playground this
naive second quantization theory. It is not to be taken seriously physically in
as far as it has indefinite Fock space, but it has nevertheless interesting
possibilities: Although the naive (quantization) theory represents a
spontaneous breakdown of the usual CPT-symmetry, we shall show that it obeys a
certain replacement for the CPT-theorem for which a proof is presented in
detail.

18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat