On M-Theory Embedding of Topologically Massive Gravity

TL;DR

This paper demonstrates how topologically massive gravity in three dimensions can be derived from a seven-dimensional gravity theory with topological terms via Kaluza-Klein reduction, linking it to M-theory and M5-branes.

Contribution

It provides a consistent embedding of topologically massive gravity into M-theory through a specific seven-dimensional reduction, establishing a connection to M5-brane charge.

Findings

Topologically massive gravity arises from seven-dimensional gravity with topological terms.

The internal four-manifold must be Einstein with a specific Pontryagin form.

The mass parameter relates to M5-brane charge and N-branes.

Abstract

We show that topologically massive gravity can be obtained by the consistent Kaluza-Klein reduction from recently constructed seven-dimensional gravity with topological terms. The internal four-manifold should be Einstein with the Pontryagin four-form constantly proportional to the volume form. We also discuss the possible lift of the system to D=11. This enables us to connect the mass parameter \tilde\mu in D=3 to the M5-brane charge. The dimensionless quantity 3/(G\tilde \mu) is discrete and proportional to N, where N is the number of M5-branes.