The Feynman propagator on a causal set.

          @misc{ scivideos_PIRSA:09110035,
            doi = {10.48660/09110035},
            url = {https://pirsa.org/09110035},
            author = {Johnston, Steven},
            keywords = {Quantum Gravity},
            language = {en},
            title = {The Feynman propagator on a causal set.},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2009},
            month = {nov},
            note = {PIRSA:09110035 see, \url{https://scivideos.org/pirsa/09110035}}
          }
          

Abstract

How sure are you that spacetime is continuous? One approach to quantum gravity, causal set theory, models spacetime as a discrete structure: a causal set. This talk begins with a brief introduction to causal sets, then describes a new approach to modelling a quantum scalar field on a causal set. We obtain the Feynman propagator for the field by a novel procedure starting with the Pauli-Jordan commutation function. The candidate Feynman propagator is shown to agree with the continuum result. This model opens the door to physical predictions for scalar matter on a causal set.