Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A Quartic Conformally Covariant Differential Operator for Arbitrary
  Pseudo-Riemannian Manifolds (Summary)
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph