PIRSA:25060013

Visions of RealTime: The Lorentz-signature gravitational path integral for fun and profit (Vision Talk)

Marolf, D. (2025). Visions of RealTime: The Lorentz-signature gravitational path integral for fun and profit (Vision Talk). Perimeter Institute. https://pirsa.org/25060013

Marolf, Donald. Visions of RealTime: The Lorentz-signature gravitational path integral for fun and profit (Vision Talk). Perimeter Institute, Jun. 24, 2025, https://pirsa.org/25060013 

          @misc{ pirsa_PIRSA:25060013,
            doi = {10.48660/25060013},
            url = {https://pirsa.org/25060013},
            author = {Marolf, Donald},
            keywords = {Quantum Gravity, Quantum Information},
            language = {en},
            title = {Visions of RealTime:  The Lorentz-signature gravitational path integral for fun and profit (Vision Talk)},
            publisher = {Perimeter Institute},
            year = {2025},
            month = {jun},
            note = {PIRSA:25060013 see, \url{https://pirsa.org}}
          }

Donald Marolf University of California, Santa Barbara

Talk numberPIRSA:25060013
DOI10.48660/25060013
Collection
Talk Type Conference
Subject

Abstract

The Euclidean gravitational action is unbounded below. As a result, even at the effective field theory level, the gravitational path integral cannot be formulated as an integral over real Euclidean geometries. I therefore review recent efforts to formulate the path integral directly in Lorentz-signature in a manner that allows general topology-changing transitions. I will also describe how this formulation resolves certain puzzles associated with computing the density of states for nearly-extremal black holes. (VIRTUAL TALK)