Mixed ’t Hooft anomalies and the Witten effect for AdS black holes
摘要
For a variety of BPS black holes in string theory, the supersymmetric index has provided a microscopic validation of the Bekenstein-Hawking formula. In the near-BPS limit, a gravitational path integral analysis previously revealed the semiclassical spectrum is modified, having a large extremal degeneracy (consistent with the index) and a mass gap up to a continuum of non-BPS black holes. Presently, we study examples in which these sharp features of the spectrum are altered due to the presence of anomalies in the form of ϑ-angle terms in the action. These may appear generally, but we focus on near-BPS dyonic AdS4 black holes in M-theory, dual to 3d