PIRSA:26090047

Video URL

https://pirsa.org/26090047

Emergent time and more from wavefunction collapse in general relativity

Lee, S. (2026). Emergent time and more from wavefunction collapse in general relativity. Perimeter Institute for Theoretical Physics. https://pirsa.org/26090047

Lee, Sung-Sik. Emergent time and more from wavefunction collapse in general relativity. Perimeter Institute for Theoretical Physics, Sep. 24, 2026, https://pirsa.org/26090047 

          @misc{ scivideos_PIRSA:26090047,
            doi = {10.48660/26090047},
            url = {https://pirsa.org/26090047},
            author = {Lee, Sung-Sik},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Emergent time and more from wavefunction collapse in general relativity},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2026},
            month = {sep},
            note = {PIRSA:26090047 see, \url{https://scivideos.org/pirsa/26090047}}
          }

Sung-Sik Lee McMaster University

Talk numberPIRSA:26090047
DOI10.48660/26090047
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

This talk is about the proposal that (1) quantum states that violate the momentum and Hamiltonian constraints represent instances of time, and (2) time evolution corresponds to the gradual collapse of an initial state toward a diffeomorphism-invariant state, driven by stochastic fluctuations of the lapse and shift. During the wavefunction collapse, the scale factor increases monotonically and thus acts as a clock. Scalar, vector, and tensor gravitons arise as physical excitations. In the long-time limit, the tensor gravitons exhibit emergent unitary dynamics, while the extra modes are damped by the non-unitary dynamics that suppress constraint-violating excitations. I will also comment on possible physical implications of these extra graviton modes.