# Non-Riemannian geometry of M-theory

## TL;DR

This paper develops a moduli-free M-theory background by embedding non-Riemannian geometry into exceptional field theory, enabling the description of non-relativistic geometries within a unified framework.

## Contribution

It introduces a novel approach to incorporate non-Riemannian geometries into ExFT, extending previous double field theory work to M-theory.

## Key findings

- Constructed a moduli-free M-theory background.
- Related the background to a topological phase of E8(8) ExFT.
- Enabled description of non-relativistic geometries within ExFT.

## Abstract

We construct a background for M-theory that is moduli free. This background is then shown to be related to a topological phase of the $\mathrm{E}_{8(8)}$ exceptional field theory (ExFT). The key ingredient in the construction is the embedding of non-Riemannian geometry in ExFT. This allows one to describe non-relativistic geometries, such as Newton-Cartan or Gomis-Ooguri-type limits, using the ExFT framework originally developed to describe maximal supergravity. This generalises previous work by Morand and Park in the context of double field theory.