PIRSA:15090009

An algebraic approach to the problem of time

(2015). An algebraic approach to the problem of time. Perimeter Institute. https://pirsa.org/15090009

An algebraic approach to the problem of time. Perimeter Institute, Sep. 03, 2015, https://pirsa.org/15090009 

          @misc{ pirsa_PIRSA:15090009,
            doi = {10.48660/15090009},
            url = {https://pirsa.org/15090009},
            author = {},
            keywords = {Quantum Gravity},
            language = {en},
            title = {An algebraic approach to the problem of time},
            publisher = {Perimeter Institute},
            year = {2015},
            month = {sep},
            note = {PIRSA:15090009 see, \url{https://pirsa.org}}
          }
Talk numberPIRSA:15090009
DOI10.48660/15090009
Collection
Talk Type Scientific Series
Subject

Abstract

An algebraic view allows one to compute properties of physical states without having to introduce an explicit Hilbert space. In relational systems without absolute time, a state cannot be completely positive once a choice for a (possibly local) internal time has been made. A more general class of `almost-positive' states is introduced in this talk, together with a discussion of their constrained dynamics.