PIRSA:22010078

Lorentzian quantum gravity and the graviton spectral function

Reichert, M. (2022). Lorentzian quantum gravity and the graviton spectral function. Perimeter Institute. https://pirsa.org/22010078

Reichert, Manuel. Lorentzian quantum gravity and the graviton spectral function. Perimeter Institute, Jan. 13, 2022, https://pirsa.org/22010078 

          @misc{ pirsa_PIRSA:22010078,
            doi = {10.48660/22010078},
            url = {https://pirsa.org/22010078},
            author = {Reichert, Manuel},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Lorentzian quantum gravity and the graviton spectral function},
            publisher = {Perimeter Institute},
            year = {2022},
            month = {jan},
            note = {PIRSA:22010078 see, \url{https://pirsa.org}}
          }

Manuel Reichert

University of Southern Denmark

Talk number
PIRSA:22010078
Collection
Talk Type
Subject
Abstract

Over the past decades, the asymptotic safety scenario has matured into a viable contender for a consistent theory of quantum gravity. However, the pressing question of unitarity is far from being settled. I will present important steps towards tackling this issue and show the first direct computation of the graviton spectral function in asymptotically safe quantum gravity with a novel Lorentzian renormalisation group approach. We find a positive graviton spectral function, showing a massless one-graviton peak and a multi-graviton continuum with an asymptotically safe scaling for large spectral values. For small spectral values, the effective field theory result is approached. I will indicate consequences for scattering amplitudes and unitarity.