PIRSA:20100012

Renormalisation and momentum dependence in Quantum Gravity

Knorr, B. (2020). Renormalisation and momentum dependence in Quantum Gravity. Perimeter Institute. https://pirsa.org/20100012

Knorr, Benjamin. Renormalisation and momentum dependence in Quantum Gravity. Perimeter Institute, Oct. 01, 2020, https://pirsa.org/20100012 

          @misc{ pirsa_PIRSA:20100012,
            doi = {10.48660/20100012},
            url = {https://pirsa.org/20100012},
            author = {Knorr, Benjamin},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Renormalisation and momentum dependence in Quantum Gravity},
            publisher = {Perimeter Institute},
            year = {2020},
            month = {oct},
            note = {PIRSA:20100012 see, \url{https://pirsa.org}}
          }

Benjamin Knorr

Nordic Institute for Theoretical Physics

Talk number
PIRSA:20100012
Collection
Talk Type
Subject
Abstract

Renormalisation in curved spacetimes is an involved subject. In contrast to renormalisation in a flat spacetime, the standard momentum representation is not directly available. Nevertheless, the momentum dependence of correlation functions is crucial to deciding whether a theory is unitary and causal. I will discuss how to define a notion of momentum dependence in gravity on a fundamental level. With this at hand, one can discuss an important quantum field theory observable: scattering cross sections. Taking the example of gravity-mediated scalar scattering, I will discuss conditions that a quantum field theory of gravity has to fulfil to have a well-behaved scattering amplitude. These can be satisfied without the introduction of massive higher spin modes as is done in string theory. Finally, I will review the status of first principle calculations of the non-perturbative momentum dependence of quantum gravity correlation functions.