Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Lorentz Force and Energy-Momentum for Off-Shell Electromagnetism   The kinematics of pre-Maxwell electrodynamics is examined and interpretations
of these fields is found through an examination of the associated Lorentz force
and the structure of the energy-momentum tensor.

33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ