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

Understand

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.