Elliptical and Purely NS Superstrata

TL;DR

This paper constructs new supersymmetric solutions in supergravity, including elliptical deformations of superstrata and novel hyper-Kähler geometries, advancing understanding of microstate geometries in string theory.

Contribution

It introduces multi-parameter supersymmetric solutions with elliptical deformations and new hyper-Kähler geometries, expanding the landscape of superstrata configurations.

Findings

Elliptical deformations of supertubes are constructed.

New elliptically-deformed hyper-Kähler geometries are found.

Scaling superstrata with S-dual NS-sector are introduced.

Abstract

We analyze the BPS equations in the ``superstratum sector'' of three-dimensional gauged supergravity. We obtain multi-parameter supersymmetric solutions that include elliptical deformations of the supertubes that underlie standard superstrata. We uplift the three-dimensional solutions to obtain the corresponding six-dimensional geometries. This yields new families of elliptically-deformed, ambi-bolar hyper-K\"ahler geometries in four dimensions with a non-tri-holomorphic $U(1)$ isometry. We also find a new family of scaling superstrata whose S-dual lives entirely within the NS-sector of supergravity, and will thus be more amenable to exact analysis using string probes. In all these new superstrata, including the scaling ones, if the momentum charge is non-zero we find that the ellipse stays away from the degeneration locus in which the ellipse becomes flat.