Softly higher-derivative massive gravity

TL;DR

This paper investigates higher-derivative massive gravity in D-dimensional spacetime, incorporating resonance mass, Chern-Simons, and Ricci-Cotton terms, analyzing graviton propagator, causality, and unitarity.

Contribution

It introduces a comprehensive analysis of higher-derivative massive gravity with additional topological terms, evaluating the graviton propagator and physical consistency in a braneworld context.

Findings

Derived the graviton propagator using Barnes-Rivers projectors.

Analyzed causality and unitarity conditions for the model.

Discussed the dispersion relations and physical viability.

Abstract

In this work, we study the higher-derivative massive gravity in $D$-dimensional space-time with the mass term arisen due to a 2-brane embedded in a $4D$ Minkowski spacetime. We consider the effect of a resonance mass term from the DGP braneworld model for the higher-derivative massive gravity. Moreover, we add the gravitational Chern-Simons and Ricci-Cotton terms to this model and evaluate the graviton propagator using a basis of Barnes-Rivers spin projectors. Using the obtained propagator, we proceed with discussing the consistency of the model, writing the dispersion relations, and analyzing causality and unitarity.