Parts | Days | Selection | Search | Updates | Downloads | Help

GR: Fachverband Gravitation und Relativitätstheorie

GR 3: Quantum Gravity II

GR 3.2: Talk

Monday, February 29, 2016, 17:05–17:25, VMP6 HS A

Effective Spacetimes from Quantum Cosmology — •Andrea Dapor — Institute for Quantum Gravity, University of Erlangen-Nürnberg

I will describe a general mechanism for the emergence of a classical spacetime from an underlying theory of quantum cosmology coupled to matter. This idea is based on QFT on quantum spacetime, and the emergent classical metric is not just the naïve expectation value of a ``metric operator'' on the quantum state of geometry. In fact, if the matter sector consists of as simple a species as a massive real scalar field, then the emergent classical metric depends explicitly on the momentum of the particle used to probe it. This is therefore an explicit realization of the concept known in the literature as ``rainbow metric'' (the name comes from the analogy with propagation of light in cristals, where photons of different colors move along different pahts). Application of this method to homogeneous isotropic Loop Quantum Cosmology will be presented, and the intensity of local Lorentz-violation will be estimated. Time permitting, I will also sketch some preliminary results in the context of anisotropic cosmologies.