Horava-Lifshitz gravity, absolute time, and objective particles in curved space

Abstract

Recently, Horava formulated a renormalizable theory of quantum gravity that reduces to general relativity at large distances but violates Lorentz invariance at small distances. The absolute time involved in this theory allows to define an objective notion of particles associated with quantization of fields in classical gravitational backgrounds. The Unruh effect and other observer-dependent notions of particles in curved space are interpreted as effects caused by interaction between the objective vacuum and the measuring apparatus made up of objective particles.