Extended massive gravity in three dimensions

TL;DR

This paper develops higher-derivative gravity theories in three dimensions using a Chern-Simons-like approach, ensuring ghost-freedom and analyzing their canonical structure, boundary charges, and holographic properties.

Contribution

It introduces a systematic method to construct ghost-free higher-derivative 3D gravity models and explores their holographic and canonical features, including the embedding of Born-Infeld gravity.

Findings

Constructed a class of ghost-free higher-derivative gravity theories

Analyzed the canonical structure and boundary charges of these models

Identified Born-Infeld gravity as a special case within the class

Abstract

Using a first order Chern-Simons-like formulation of gravity we systematically construct higher-derivative extensions of general relativity in three dimensions. The construction ensures that the resulting higher-derivative gravity theories are free of scalar ghosts. We canonically analyze these theories and construct the gauge generators and the boundary central charges. The models we construct are all consistent with a holographic c-theorem which, however, does not imply that they are unitary. We find that Born-Infeld gravity in three dimensions is contained within these models as a subclass.