Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Zero-energy edge states and their origin in particle-hole symmetric
  systems: symmetry and topology   We propose a criterion to determine the existence of zero-energy edge states
for a class of particle-hole symmetric systems. A loop is assigned for each
system, and its topology and a symmetry play an essential role. Applications to
d-wave superconductors are demonstrated.

2
The categories of this paper are: math
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg