Probing the string axiverse by gravitational waves from Cygnus X-1

Abstract

In the axiverse scenario, a massive scalar field (string axion) forms a cloud around a rotating black hole (BH) by superradiant instability and emits continuous gravitational waves (GWs). We examine constraints on the string axion parameters that can be obtained from GW observations. If no signal is detected in a targeted search for GWs from Cygnus X-1 in the LIGO data, the decay constant $f_a$ must be smaller than the GUT scale in the mass range $1.1\times 10^{-12}\mathrm{eV}<\mu <2.5\times 10^{-12}\mathrm{eV}$. Constraints from invisible isolated BHs are also discussed.

8 pages, 3 figures, to be published in PTEP Letters

References in corpus (6)

• Instability of the massive Klein-Gordon field on the Kerr spacetime
• The Breaking Strain of Neutron Star Crust and Gravitational Waves
• Upper limits on gravitational wave emission from 78 radio pulsars
• Bosenova collapse of axion cloud around a rotating black hole
• The Origin of Black Hole Spin in Galactic Low-Mass X-ray Binaries
• Einstein@Home all-sky search for periodic gravitational waves in LIGO S5 data

Cited by in corpus (4)

• Stochastic and resolvable gravitational waves from ultralight bosons
• Ultralight boson cloud depletion in binary systems
• Constraints on ultralight scalar bosons within black hole spin measurements from LIGO-Virgo's GWTC-2
• Effective field theory for black holes with induced scalar charges