Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dark Matter Axion Clump Resonance of Photons   Recently there has been interest in the physical properties of dark matter
axion condensates. Due to gravitational attraction and self-interactions, they
can organize into spatial localized clumps, whose properties were examined by
us in Refs. [1, 2]. Since the axion condensate is coherently oscillating, it
can conceivably lead to parametric resonance of photons, leading to exponential
growth in photon occupancy number and subsequent radio wave emission. We show
that while resonance always exists for spatially homogeneous condensates, its
existence for a spatially localized clump condensate depends sensitively on the
size of clump, strength of axion-photon coupling, and field amplitude. By
decomposing the electromagnetic field into vector spherical harmonics, we are
able to numerically compute the resonance from clumps for arbitrary parameters.
We find that for spherically symmetric clumps, which are the true BEC ground
states, the resonance is absent for conventional values of the QCD axion-photon
coupling, but it is present for axions with moderately large couplings, or into
hidden sector photons, or from scalar dark matter with repulsive interactions.
We extend these results to non-spherically symmetric clumps, organized by
finite angular momentum, and find that even QCD axion clumps with conventional
couplings can undergo resonant decay for sufficiently large angular momentum.
We discuss possible astrophysical consequences of these results, including the
idea of a pile-up of clump masses and rapid electromagnetic emission in the sky
from mergers.

23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
19
The categories of this paper are: eess