Nonlocal Quantum Gravity

by Dr Leonardo Modesto

Wednesday 7 Jul 2021, 14:30 → 16:30 Europe/Rome

281 (Department of Physics and Astronomy)

In the quantum field theory framework, ``Nonlocal Quantum gravity'' (with or without matter) turns out to be a good candidate for all fundamental interactions compatible with classical stability, perturbative unitarity, causality, and finiteness at quantum.  The latter property implies that there is no Weyl anomaly and the theory turns out to be conformal invariant at classical as well at quantum level. Therefore, nonlocal quantum gravity is a conformal invariant theory in the spontaneously broken phase of the Weyl symmetry. As an implication of the theory, the anomaly-free Weyl conformal symmetry elegantly solves the problem of spacetime singularities, otherwise unavoidable in a generally covariant local or non-local gravitational theory. According to the last statement, we provide explicit examples of singularity-free black hole solutions, having finite curvature invariants and, most importantly, geodetically complete. Indeed, no massive or massless particle can reach the singularity in a finite amount of proper time or of affine parameter. Finally, we will propose a new scenario for the early universe in nonlocal finite quantum gravity based on conformal invariance and as an alternative to inflation.