Relational time and intrinsic decoherence.

          @misc{ scivideos_PIRSA:08090072,
            doi = {10.48660/08090072},
            url = {https://pirsa.org/08090072},
            author = {Milburn, Gerard},
            keywords = {Quantum Foundations},
            language = {en},
            title = {Relational time and intrinsic decoherence.},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2008},
            month = {sep},
            note = {PIRSA:08090072 see, \url{https://scivideos.org/pirsa/08090072}}
          }
          

Abstract

One approach to the problem of time in canonical quantum gravity is to use correlations between a carefully chosen physical system and all other physical systems to provide a simulacrum of time. Time emerges as an ordering of correlated measurement results. In many ways this is an echo of an idea introduced by Poincare to give a geometric description of dynamical systems. Pullin and Gambini have addressed some objections to this approach using a consistent discretization, but in so doing introduce an intrinsic decoherence mechanism into physical theories. In this talk I will show how this approach leads to a simple form of intrinsic decoherence that has possible experimental consequences, among which are modifications to the dispersion relations of the electromagnetic field. This form of decoherence enables the emergence of semiclassical behavior of large systems.