Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unification of Gravity with Electromagnetism   Principles of Maxwell, Lorentz, Milne, Dirac and Feynman are combined to
unify gravity with electromagnetism.

2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph