Weyl-gauging of Topologically Massive Gravity

TL;DR

This paper develops a Weyl-invariant extension of topologically massive gravity that naturally includes massive gauge fields and scalar fields, with mass generation through symmetry breaking, and explores its implications in different spacetime backgrounds.

Contribution

It introduces a novel Weyl-invariant formulation of topologically massive gravity that unifies gravity and gauge fields with mass generation via symmetry breaking.

Findings

Masses generated via symmetry breaking in flat and curved backgrounds.

The theory includes a massive spin-2 and a massive spin-1 excitation.

Chiral gravity does not emerge in AdS backgrounds, but is possible in dS backgrounds.

Abstract

We construct a Weyl-invariant extension of topologically massive gravity which, remarkably, turns out to include topologically massive electrodynamics, with a Proca mass term, conformally coupled to a scalar field. The action has no dimensionful parameters, therefore, the masses are generated via symmetry breaking either radiatively in flat backgrounds or spontaneously in constant curvature backgrounds. The broken phase of the theory, generically, has a single massive spin-2 and a massive spin-1 excitation. Chiral gravity in asymptotically anti-de Sitter spacetimes does not arise as a low energy theory, while chiral gravity in de Sitter spacetime is not ruled out.