Superradiance Exclusions in the Landscape of Type IIB String Theory

TL;DR

This study uses black hole superradiance to constrain axion-like particles in a vast landscape of string theory compactifications, excluding significant portions of models based on astrophysical black hole data.

Contribution

It provides the first large-scale analysis of superradiance constraints across over 200,000 Calabi-Yau manifolds in type IIB string theory, explicitly computing axion spectra at multiple moduli points.

Findings

Excludes about 50% of models at the tip of the Kähler cone at 95% confidence level.

Excludes up to 7% of models at a point suitable for the Standard Model.

Constraints diminish with increasing Hodge number, nearly vanishing at h^{1,1}=100.

Abstract

We obtain constraints from black hole superradiance in an ensemble of compactifications of type IIB string theory. The constraints require knowing only the axion masses and self-interactions, and are insensitive to the cosmological model. We study more than $2 \cdot 10^5$ Calabi-Yau manifolds with Hodge numbers $1\leq h^{1,1}\leq 491$ and compute the axion spectrum at two reference points in moduli space for each geometry. Our computation of the classical theory is explicit, while for the instanton-generated axion potential we use a conservative model. The measured properties of astrophysical black holes exclude parts of our dataset. At the point in moduli space corresponding to the tip of the stretched K\"{a}hler cone, we exclude $\approx 50\%$ of manifolds in our sample at 95% C.L., while further inside the K\"{a}hler cone, at an extremal point for realising the Standard Model, we exclude a maximum of $\approx 7\%$ of manifolds at $h^{1,1}=11$, falling to nearly zero by $h^{1,1}=100$.