The Case for Renormalizable Quantum Gravity

by Luca Buoninfante (Nordita)

Thursday 12 Oct 2023, 13:30 → 14:30 Europe/Copenhagen

Aud A

In the context of perturbative quantum field theory (QFT), the addition of quadratic-curvature invariants to the Einstein-Hilbert action makes it possible to achieve strict renormalizability in four dimensions. This theory exhibits unusual features due to an additional massive spin-2 ghost particle. In this talk, we will discuss several interesting implications due to the ghost-like nature of the additional spin-2 field. In particular, we are going to argue that despite the presence of the ghost and actually thanks to it, Quadratic Gravity can provide a consistent QFT description of the gravitational interaction at a fundamental level and explain new physics beyond Einstein's general relativity, e.g., it offers a natural explanation for the inflationary phase in the early Universe.