Comments on Topologically Massive Gravity with Propagating Torsion

TL;DR

This paper explores the effects of incorporating torsion into 3D Einstein-Chern-Simons gravity, examining how it influences physical modes and unitarity with higher-derivative modifications.

Contribution

It analyzes the consequences of torsion in 3D gravity and assesses unitarity issues with added higher-derivative terms.

Findings

Torsion can activate non-physical modes in the spectrum.

Higher-derivative terms impact tree-level unitarity.

Torsion's role in the physical viability of 3D gravity models.

Abstract

We study and discuss some of the consequences of the inclusion of torsion in 3D Einstein-Chern-Simons gravity. Torsion may trigger the excitation of non-physical modes in the spectrum. Higher-derivative terms are then added up and tree-level unitarity is contemplated.