PIRSA:22120046

Non-locality in Quantum Gravity

Buoninfante, L. (2022). Non-locality in Quantum Gravity. Perimeter Institute. https://pirsa.org/22120046

Buoninfante, Luca. Non-locality in Quantum Gravity. Perimeter Institute, Dec. 08, 2022, https://pirsa.org/22120046 

          @misc{ pirsa_PIRSA:22120046,
            doi = {10.48660/22120046},
            url = {https://pirsa.org/22120046},
            author = {Buoninfante, Luca},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Non-locality in Quantum Gravity},
            publisher = {Perimeter Institute},
            year = {2022},
            month = {dec},
            note = {PIRSA:22120046 see, \url{https://pirsa.org}}
          }

Luca Buoninfante

Nordic Institute for Theoretical Physics

Talk number
PIRSA:22120046
Collection
Talk Type
Subject
Abstract

A natural way to extend Einstein's General Relativity to the high-energy regime is to introduce quadratic curvature operators, which give rise to a renormalizable gravitational Lagrangian in four dimensions. However, this theory turns out to be pathological due to an additional massive spin-2 ghost that causes classical instabilities and breaks perturbative unitarity at the quantum level. In this talk, we investigate which principles of QFT are usually affected when higher-order derivative operators are present in a Lagrangian, and show that one possibility to avoid ghosts is giving up locality. In fact, the emergence of non-local physics at short distances and high energies is a common prediction for various quantum gravity approaches. We propose a model-independent approach to constrain the non-local Lagrangian in quantum gravity, thus providing a novel scenario in which different quantum gravity programs can be fruitfully contrasted in terms of foundational concepts and computational methods.

Zoom link:  https://pitp.zoom.us/j/96167652193?pwd=OWFDV1JXVGxLdE1qMHo4N3ZKcDByQT09