Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Imaging of anomalous internal reflections of hyperbolic
  phonon-polaritons in hexagonal boron nitride
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga