Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Duffin-Kemmer-Petiau Theory in the Causal Approach   In this paper we consider the scalar sector of Duffin-Kemmer-Petiau theory in
the framework of Epstein-Glaser causal method. We calculate the lowest order
distributions for Compton scattering, vacuum polarization, self-energy and
vertex corrections. By requiring gauge invariance of the theory we recover, in
a natural way, the scalar propagator of the usual effective theory.

26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph