Massive Spin-2 fields of Geometric Origin in Curved Spacetimes

TL;DR

This paper investigates a model with torsion and metric as dynamical fields, featuring a massive spin-2 particle in the torsion, and demonstrates its classical consistency in curved spacetimes such as de Sitter and anti-de Sitter backgrounds.

Contribution

The study extends the known ghost- and tachyon-free properties of the model from Minkowski to curved Einstein spacetimes, showing its classical consistency.

Findings

Model remains ghost- and tachyon-free in curved backgrounds

Massive spin-2 mode resides in torsion, not metric

No additional pathologies found in Einstein spaces

Abstract

We study the consistency of a model which includes torsion as well as the metric as dynamical fields and has massive spin-2 particle in its spectrum. The massive spin-2 mode resides in the torsion, rather than in the metric. It is known that this model is tachyon- and ghost-free in Minkowski background. We show that this property remains valid and no other pathologies emerge in de Sitter and anti-de Sitter backgrounds, with some of our results extending to arbirary Einstein space backgrounds. This suggests that the model is consistent, at least at the classical level, unlike, e.g., the Fierz--Pauli theory.