Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Motion of Spin 1/2 Massless Particle in a Curved Spacetime. I.
  Lagrangian Approach
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph