On a Three-Dimensional Gravity Model with Higher Derivatives

Abstract

The purpose of this work is to present a model for 3D massive gravity with topological and higher-derivative terms. Causality and unitarity are discussed at tree-level. Power-counting renormalizability is also contemplated.Comment: 9 pages, Latex, no figures; to be published in Gen. Rel. Gra

Some quantum aspects of three-dimensional Einstein-Chern-Simons-Proca massive gravity

“…With the reality and conservation of the energy-momentum tensor (as discussed in refs. [1,3,5]), the tree-level unitarity will be ensured. Also, the explicit calculation of the residues of the propagator at the simple poles shall guarantee that negative-norm states (ghosts) decouple form physical amplitudes.…”

“…In the following, we are going to discuss the unitarity of the Einstein-Chern-Simons-Proca model. As done in [3,5], here too, we proceed to this analysis by studying the properties of the current-current transition amplitude,…”

Unavoidable Conflict Between Massive Gravity Models and Massive Topological Terms

“…The particle content related to the first situation is two massive spin-2 physical particles, one massless spin-2 nonpropagating particle and one massive spin-0 ghost, whereas that concerning the second one is one massive spin-2 physical particle, one massive spin-2 ghost, one nonpropagating graviton and one massive spin-0 ghost. Therefore, unlike the claim in the literature 4 , THDG with Einstein's term with the "wrong" sign is tree nonunitary. Note that the authors of Ref.…”

Algorithm for Probing the Unitarity of Topologically Massive Models

“…According to a somewhat obscure unitarity lore it is expected that the operation of augmenting a non-topological massive gravity model through the topological term would transform the non-unitary systems into unitary ones and preserve the unitarity of the originally unitary models. This false idea is, perhaps, responsible for the claims in the literature concerning the pseudo-unitarity of both topologically massive Fierz-Pauli gravity (TMFPG) (Pinheiro et al, 1997a,b) and TMHDG (Pinheiro et al, 1997c). The authors of these works wrongly state that these models are unitary.…”