Constrains of the axion-like particle from black hole spin superradiance

TL;DR

This paper refines constraints on axion-like particle masses using black hole spin data and an improved superradiance formula, revealing two favored mass ranges and emphasizing the impact of merger timescales on evidence strength.

Contribution

It introduces an updated superradiance calculation and Bayesian analysis of merger timescales to better constrain axion-like particle masses from black hole observations.

Findings

Identified two favored axion mass ranges between 7.94×10⁻¹³ eV and 1.74×10⁻¹² eV.

Showed the evidence for certain mass ranges increases significantly when considering merger timescales.

Demonstrated the robustness of favored mass ranges against prior assumptions.

Abstract

The mass of the axion-like particles could be constrained by the observed black hole spin distribution. In this work, we update the previous calculations using the recently improved superradiance formula, which is much more accurate. The effect of the merger time scale is also carefully investigated with Bayesian analysis. After integration of the merger time $\tau_\mathrm{M}$, we find two favoured mass ranges $7.94\times10^{-13}~\text{eV}\leq\mu\leq8.71\times10^{-13}~\text{eV}$ and $1.44\times10^{-12}~\text{eV}\leq\mu\leq1.74\times10^{-12}~\text{eV}$ . These two favored ranges do not depend on the prior distribution of the $\tau_\mathrm{M}$. We also find the strength of evidence for the range $-12.80\leq\log_{10}(\mu/\text{eV})\leq-12.34$, which is excluded in the analysis with fixed $\tau_\text{M}$, could increase by several orders of magnitude with $\tau_\mathrm{M}$ averaged.