Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: N- and 1-time Classical Description of N-body Relativistic Kinematics
  and the Electromagnetic Interaction   The intrinsic covariant 1-time description (rest-frame instant form) for N
relativistic scalar particles is defined. The system of N charged scalar
particles plus the electromagnetic field is described in this way: the study of
its Dirac observables allows the extraction of the Coulomb potential from field
theory and the regularization of the classical self-energy by using
Grassmann-valued electric charges. The 1-time covariant relativistic
statistical mechanics is defined.

22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con