Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: In-plane anisotropy of spin excitations in the normal and
  superconducting states of underdoped YBa$_2$Cu$_3$O$_{6+x}$
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex