Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Black hole superradiance and polarization-dependent bending of light   An inhomogeneous pseudo-scalar field configuration behaves like an optically
active medium. Consequently, if a light ray passes through an axion cloud
surrounding a Kerr black hole, it may experience a polarization-dependent
bending. We explore the size and relevance of such effect considering both the
QCD axion and a generic axion-like particle.

32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph