Kaluza-Klein spectrometry for ${\rm AdS_{3}}$ vacua

TL;DR

This paper introduces a method using exceptional field theory to efficiently compute Kaluza-Klein spectra around AdS3 vacua in various supergravity theories, regardless of symmetry preservation.

Contribution

It provides a universal formalism for calculating Kaluza-Klein spectra from higher-dimensional supergravity truncations, applicable to diverse vacua.

Findings

Computed spectra for six-dimensional supergravities on AdS3×S3.

Analyzed spectra for type II supergravity on AdS3×S3×S3×S1.

Demonstrated the method's efficiency and broad applicability.

Abstract

We use exceptional field theory to compute Kaluza-Klein mass spectra around ${\rm AdS_{3}}$ vacua that sit in half-maximal gauged supergravity in three dimensions. The formalism applies to any vacuum that arises from a consistent truncation of higher-dimensional supergravity, no matter what symmetries are preserved. We illustrate its efficiency by computing the spectra of ${\cal N}=(2,0)$ and ${\cal N}=(1,1)$ six-dimensional supergravities on ${\rm AdS_{3}}\times S^{3}$ and of type II supergravity on ${\rm AdS_{3}}\times S^{3}\times S^{3}\times S^{1}$.