Particle Propagators from Discrete Spacetime


Johnston, S. (2008). Particle Propagators from Discrete Spacetime. Perimeter Institute. https://pirsa.org/08040043


Johnston, Steven. Particle Propagators from Discrete Spacetime. Perimeter Institute, Apr. 14, 2008, https://pirsa.org/08040043


          @misc{ pirsa_08040043,
            doi = {10.48660/08040043},
            url = {https://pirsa.org/08040043},
            author = {Johnston, Steven},
            keywords = {Particle Physics},
            language = {en},
            title = {Particle Propagators from Discrete Spacetime},
            publisher = {Perimeter Institute},
            year = {2008},
            month = {apr},
            note = {PIRSA:08040043 see, \url{https://pirsa.org}}

Steven Johnston Imperial College London

Talk Type Scientific Series


How sure are you that spacetime is continuous? One of the more radical approaches to quantum gravity, causal set theory, models spacetime as a discrete structure: a causal set. Allowing the possibility that spacetime is discrete then how should we do physics on it? Carrying over the usual continuum descriptions in terms of differential equations seems like a difficult option. This talk begins with a brief introduction to causal sets then describes an approach to modelling the propagation of scalar particles on a causal set. We obtain the continuum causal retarded propagator by summing quantum mechanical amplitudes assigned to paths in the causal set - a kind of \'discrete path integral\' that agrees with the continuum result. The propagator so obtained should serve as a building block towards a model for quantum field theory on a causal set.