Matter Induced Bimetric Actions for Gravity

TL;DR

This paper investigates the renormalization group flow of a bimetric gravitational effective action with scalar matter, demonstrating asymptotic safety in a large N expansion despite the extended theory space.

Contribution

It introduces a bimetric truncation with background dependence and analyzes fixed points, showing asymptotic safety in an enlarged theory space.

Findings

Asymptotic safety confirmed in bimetric setting

Fixed points identified in large N limit

Neglecting metric contributions simplifies analysis

Abstract

The gravitational effective average action is studied in a bimetric truncation with a nontrivial background field dependence, and its renormalization group flow due to a scalar multiplet coupled to gravity is derived. Neglecting the metric contributions to the corresponding beta functions, the analysis of its fixed points reveals that, even on the new enlarged theory space which includes bimetric action functionals, the theory is asymptotically safe in the large $N$ expansion.