Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two-Time Quantum Mechanics   A two-time quantum theory of a system of two particles with the direct
electromagnetic interaction based on a quantum version of the action principle
is considered. An analog of Schrodinger equation for the system is obtained.

7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs