Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Kermions   In the framework of quantum field theory in curved space-time, we study the
quantization of a massless fermion field on a non-extremal Kerr black hole. The
key theme in this note is the fundamental difference between scalar and fermion
fields for the process of defining quantum states. In particular, we define two
new states for fermions on Kerr which cannot be defined for quantum scalar
fields on Kerr. These two states are the analogues of the standard Boulware and
Hartle-Hawking states on a Schwarzschild black hole.

6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci