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 $1leq h^{1,1}leq 491$ 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 $h^{1,1}=100$.
Download