From Lee-Wick Models to Quantum Gravity, Fakeons and the Violation of Microcausality

Study of the mathematical aspects of Lee-Wick quantum field theories and their relation with quantum gravity. In particular, it is proved that the models satisfy perturbative unitarity. The proof is achieved by reformulating them as nonanalytically Wick rotated Euclidean theories. From these results, a unique, renormalizable and unitary theory of quantum gravity is identified by means of a novel quantization procedure, named “fakeon prescription”. The new model of gravitational interactions is studied in its theoretical and phenomenological aspects. The model is compared with other quantum gravity theories, pointing out their physical difference.