Quantum discreteness and spacetime causality: what's in the mix?

          @misc{ pirsa_PIRSA:24090094,
            doi = {10.48660/24090094},
            url = {https://pirsa.org/24090094},
            author = {Surya, Sumati},
            keywords = {Quantum Foundations, Quantum Information},
            language = {en},
            title = {Quantum discreteness and spacetime causality: what{\textquoteright}s in the mix?},
            publisher = {Perimeter Institute},
            year = {2024},
            month = {sep},
            note = {PIRSA:24090094 see, \url{https://pirsa.org}}
          }
          

Abstract

The notion of causality is intimately tied to both, a transitive ordering on events, and the possibility of unrelated events. Thus, any causality structure is a partially ordered set or poset. This is the case in Lorentzian spacetime, which possesses a single time direction. In causal set quantum gravity, this spacetime causality structure is "first quantised" by discretising it. However, as with any dynamical quantum theory of spacetime, background notions of causality are insufficient. I will discuss how ordering and discreteness, as manifested in the sequential growth paradigm, provide a broad framework for quantum dynamical notions of causality.