Observational prospects of self-interacting scalar superradiance with next-generation gravitational-wave detectors

Journal Article · 18 December 2024 · Classical and Quantum Gravity

DOI: https://doi.org/10.1088/1361-6382/ad96ff · OSTI ID:2482570

Collaviti, Spencer ; Sun, Ling; Galanis, Marios ; Baryakhtar, Masha

Abstract Current- and next-generation gravitational-wave observatories may reveal new, ultralight bosons. Through the superradiance process, these theoretical particle candidates can form clouds around astrophysical black holes and result in detectable gravitational-wave radiation. In the absence of detections, constraints—contingent on astrophysical assumptions—have been derived using LIGO-Virgo-KAGRA data on boson masses. However, the searches for ultralight scalars to date have not adequately considered self-interactions between particles. Self-interactions that significantly alter superradiance dynamics are generically present for many scalar models, including axion-like dark matter candidates and string axions. We implement the most complete treatment of particle self-interactions available to determine the gravitational-wave signatures expected from superradiant scalar clouds and revisit the constraints obtained in a past gravitational-wave search targeting the black hole in Cygnus X-1. We also project the reach of next-generation gravitational-wave observatories to scalar particle parameter space in the mass-coupling plane. We find that while proposed observatories have insufficient reach to self-interactions that can halt black hole spin-down, next-generation observatories are essential for expanding the search beyond gravitational parameter space and can reach a mass and interaction scale of $\sim {10}^{-13}$ –10 ⁻¹² eV $/c^2$ and $\gtrsim {10}^{17}$ GeV, respectively.

• Sponsoring Organization: USDOE
• Grant/Contract Number: SC0024375
• OSTI ID: 2482570
• Journal Information: Classical and Quantum Gravity, Journal Name: Classical and Quantum Gravity Journal Issue: 2 Vol. 42; ISSN 0264-9381
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United Kingdom
• Language: English