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Discovering the QCD Axion with Black Holes and Gravitational Waves

6 Pith papers cite this work. Polarity classification is still indexing.

6 Pith papers citing it
abstract

Advanced LIGO may be the first experiment to detect gravitational waves. Through superradiance of stellar black holes, it may also be the first experiment to discover the QCD axion with decay constant above the GUT scale. When an axion's Compton wavelength is comparable to the size of a black hole, the axion binds to the black hole, forming a "gravitational atom." Through the superradiance process, the number of axions occupying the bound levels grows exponentially, extracting energy and angular momentum from the black hole. Axions transitioning between levels of the gravitational atom and axions annihilating to gravitons can produce observable gravitational wave signals. The signals are long-lasting, monochromatic, and can be distinguished from ordinary astrophysical sources. We estimate up to O(1) transition events at aLIGO for an axion between 10^-11 and 10^-10 eV and up to 10^4 annihilation events for an axion between 10^-13 and 10^-11 eV. In the event of a null search, aLIGO can constrain the axion mass for a range of rapidly spinning black hole formation rates. Axion annihilations are also promising for much lighter masses at future lower-frequency gravitational wave observatories; the rates have large uncertainties, dominated by supermassive black hole spin distributions. Our projections for aLIGO are robust against perturbations from the black hole environment and account for our updated exclusion on the QCD axion of 6*10^-13 eV < ma < 2*10^-11 eV suggested by stellar black hole spin measurements.

citation-role summary

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citation-polarity summary

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UNVERDICTED 6

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representative citing papers

Scalar fields around black hole binaries in LIGO-Virgo-KAGRA

gr-qc · 2025-10-20 · unverdicted · novelty 6.0

Semi-analytic waveform model for scalar environments around black hole binaries is validated against numerical relativity and applied to LIGO-Virgo-KAGRA data to obtain upper limits on scalar densities with tentative evidence in GW190728.

Gravitational Atoms from Topological Stars

gr-qc · 2025-11-13 · unverdicted · novelty 5.0

Bound states of a massive scalar field around topological stars form strictly normal modes, producing a hydrogen-like spectrum when the Compton wavelength exceeds the star size and localized states otherwise.

High-frequency gravitational wave transients from superradiance

gr-qc · 2026-04-01 · unverdicted · novelty 5.0

Ultralight boson clouds around primordial black holes emit high-frequency gravitational wave transients via superradiance and binary-driven transitions, but the signals fall below current detector sensitivity at plausible distances.

Superradiance -- the 2020 Edition

gr-qc · 2015-01-26 · unverdicted · novelty 4.0

Black-hole superradiance extracts energy via the ergoregion and can trigger instabilities with applications to dark matter, beyond-Standard-Model physics, and laboratory analogs.

citing papers explorer

Showing 6 of 6 citing papers.

  • Constraining interacting dark energy models with black hole superradiance astro-ph.CO · 2025-11-20 · unverdicted · none · ref 28 · internal anchor

    Black hole superradiance constrains the coupling strength in interacting dark energy-dark matter models through modifications to the effective mass of ultralight bosons in two scenarios.

  • Scalar fields around black hole binaries in LIGO-Virgo-KAGRA gr-qc · 2025-10-20 · unverdicted · none · ref 129 · internal anchor

    Semi-analytic waveform model for scalar environments around black hole binaries is validated against numerical relativity and applied to LIGO-Virgo-KAGRA data to obtain upper limits on scalar densities with tentative evidence in GW190728.

  • Search for high-frequency gravitational waves via re-analysis of cavity axion data hep-ex · 2025-11-21 · unverdicted · none · ref 45 · internal anchor

    Reanalysis of CAPP-12T axion data sets 90% CL limits on HFGW strain down to 3.9e-21 at 5.311 GHz and excludes certain 10^{-6} solar mass black holes within 0.01 AU via superradiance interpretation.

  • Gravitational Atoms from Topological Stars gr-qc · 2025-11-13 · unverdicted · none · ref 68 · internal anchor

    Bound states of a massive scalar field around topological stars form strictly normal modes, producing a hydrogen-like spectrum when the Compton wavelength exceeds the star size and localized states otherwise.

  • High-frequency gravitational wave transients from superradiance gr-qc · 2026-04-01 · unverdicted · none · ref 16

    Ultralight boson clouds around primordial black holes emit high-frequency gravitational wave transients via superradiance and binary-driven transitions, but the signals fall below current detector sensitivity at plausible distances.

  • Superradiance -- the 2020 Edition gr-qc · 2015-01-26 · unverdicted · none · ref 103 · internal anchor

    Black-hole superradiance extracts energy via the ergoregion and can trigger instabilities with applications to dark matter, beyond-Standard-Model physics, and laboratory analogs.