Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Modified Dirac Equation   We consider the behavior of the particles at ultra relativistic energies, for
both the Klein-Gordon and Dirac equations. We observe that the usual
description is valid for energies such that we are outside the particle's
Compton wavelength. For higher energies however, both the Klein-Gordon and
Dirac equations get modified and this leads to some new effects for the
particles, including the appearance of anti particles with a slightly different
energy.

15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph