Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gravitational Waves and Possible Fast Radio Bursts from Axion Clumps   The axion objects such as axion mini-clusters and axion clouds around
spinning black holes induce parametric resonances of electromagnetic waves
through the axion-photon interaction. In particular, it has been known that the
resonances from the axion with the mass around $10^{-6}$eV may explain the
observed fast radio bursts (FRBs). Here we argue that similar bursts of high
frequency gravitational waves, which we call the fast gravitational wave bursts
(FGBs), are generated from axion clumps with the presence of gravitational
Chern-Simons (CS) coupling. The typical frequency is half of the axion mass,
which in general can range from kHz to GHz. We also discuss the secondary
gravitational wave production associated with FRB, as well as the possible host
objects of the axion clouds, such as primordial black holes with typical masses
around $10^{-5}M_{\odot}$. Future detections of FGBs together with the observed
FRBs are expected to provide more evidence for the axion.

26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci