PIRSA:21060084

Video URL

https://pirsa.org/21060084

Time symmetry in operational theories

Hardy, L. (2021). Time symmetry in operational theories. Perimeter Institute for Theoretical Physics. https://pirsa.org/21060084

Hardy, Lucien. Time symmetry in operational theories. Perimeter Institute for Theoretical Physics, Jun. 04, 2021, https://pirsa.org/21060084 

          @misc{ scivideos_PIRSA:21060084,
            doi = {10.48660/21060084},
            url = {https://pirsa.org/21060084},
            author = {Hardy, Lucien},
            keywords = {Quantum Foundations},
            language = {en},
            title = {Time symmetry in operational theories},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2021},
            month = {jun},
            note = {PIRSA:21060084 see, \url{https://scivideos.org/index.php/pirsa/21060084}}
          }

Lucien Hardy Perimeter Institute for Theoretical Physics

Talk numberPIRSA:21060084
DOI10.48660/21060084
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

The standard operational probabilistic framework (within which Quantum Theory can be formulated) is time asymmetric.  This is clear because the conditions on allowed operations include a time asymmetric causality condition.  This causality condition enforces that future choices do not influence past events.  To formulate operational theories in a time symmetric way I modify the basic notion of an operation allowing classical incomes as well as classical outcomes.  I provide a new time symmetric causality condition which I call double causality.  I apply these ideas to Quantum Theory proving, along the way, a time symmetric version of the Stinespring extension theorem using double causality.  I also propose the idea of a conditional frame of reference.  We can transform from the time symmetric frame of reference to a forward or a backward frame of reference.  This talk is based on arXiv:2104.00071.