CENTRA Seminar - Piecewise linear quantum gravity - 22 junho 2017

We describe a quantum theory of gravity which is based on the assumption that the short-distance spacetime structure is described by a piecewise linear four-manifold. The corresponding classical theory has finitely many degrees of freedom and it is described by the Regge action. The path integral can be made finite by an appropriate choice of the measure and the corresponding effective action can be approximated by the effective action for quantum field theory for General Relativity with a physical cutoff. When matter is coupled, one can show that the spectrum of the cosmological constant is continuous and that the observed value belongs to the spectrum.