Publication : t19/021

Abstract:
Superstrata are smooth horizonless microstate geometries for the supersymmetric D1-D5-P black hole in type IIB supergravity, and these geometries have well-understood CFT duals. ``Supertstratum states'' correspond to the supergraviton gas, and are obtained by breaking the CFT into ``strands'' and acting on each strand with the ``small,'' anomaly free superconformal generators. We show that the recently-constructed supercharged superstrata represent a final and crucial component for the construction of supertstratum states. Holography requires the supergravity solutions to have the same number of moduli as the CFT states. We discuss how smoothness of the original superstrata placed constraints on the moduli that appear unphysical from the CFT perspective. We show that the inclusion of supercharged superstrata states obviates these constraints and leads to supergravity solutions with precisely the correct number of parameters. We use a hybrid of the original and supercharged superstrata to construct the families of single-mode superstrata that still have free moduli after one has fixed the asymptotic charges of the system and we discuss how they can generate multi-mode superstrata without inducing singularities. We also study scalar wave perturbation in a particular family of such solutions and show that the mass gap depends on the free moduli. This can have interesting implications for superstrata at non-zero temperature.