Minimal Massive 3D Gravity Unitarity Redux
arXiv:1411.1970 · doi:10.1088/0264-9381/32/8/085003
Abstract
A geometrical analysis of the bulk and anti-de Sitter boundary unitarity conditions of 3D "Minimal Massive Gravity" (MMG) (which evades the "bulk/boundary clash" of Topologically Massive Gravity) is used to extend and simplify previous results, showing that unitarity selects, up to equivalence, a connected region in parameter space. We also initiate the study of flat-space holography for MMG. Its relevant flat space limit is a deformation of 3D conformal gravity; the deformation is both non-linear and non-conformal, implying a linearisation instability.
15 pages. Two figures. Minor corrections plus extended discussion of allowed parameter space in v2. Improved figures, additional paragraph in conclusions and additional references in v3. Spurious page headers removed in v4