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General Relativity and Quantum Cosmology, gr-qc, Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE,High Energy Physics - Phenomenology, hep-ph,High Energy Physics - Theory, hep-th
Abstract:
Ultralight bosons can induce superradiant instabilities in spinning black
holes, tapping their rotational energy to trigger the growth of a bosonic
condensate. Possible observational imprints of these boson clouds include (i)
direct detection of the nearly monochromatic (resolvable or stochastic)
gravitational waves emitted by the condensate, and (ii) statistically
significant evidence for the formation of "holes" at large spins in the spin
versus mass plane (sometimes also referred to as "Regge plane") of
astrophysical black holes. In this work, we focus on the prospects of LISA and
LIGO detecting or constraining scalars with mass in the range $m_s\in
[10^{-19},\,10^{-15}]$ eV and $m_s\in [10^{-14},\,10^{-11}]$ eV, respectively.
Using astrophysical models of black-hole populations and black-hole
perturbation theory calculations of the gravitational emission, we find that
LIGO could observe a stochastic background of gravitational radiation in the
range $m_s\in [2\times 10^{-13}, 10^{-12}]$ eV, and up to $\sim 10^4$
resolvable events in a $4$-year search if $m_s\sim 3\times 10^{-13}\,{\rm eV}$.
LISA could observe a stochastic background for boson masses in the range
$m_s\in [5\times 10^{-19}, 5\times 10^{-16}]$, and up to $\sim 10^3$ resolvable
events in a $4$-year search if $m_s\sim 10^{-17}\,{\rm eV}$. LISA could further
measure spins for black-hole binaries with component masses in the range
$[10^3, 10^7]~M_\odot$, which is not probed by traditional spin-measurement
techniques. A statistical analysis of the spin distribution of these binaries
could either rule out scalar fields in the mass range $[4 \times 10^{-18},
10^{-14}]$ eV, or measure $m_s$ with ten percent accuracy if light scalars in
the mass range $[10^{-17}, 10^{-13}]$ eV exist.