Decoherence and the (non)emergence of classicality.

          @misc{ scivideos_PIRSA:08090074,
            doi = {10.48660/08090074},
            url = {https://pirsa.org/08090074},
            author = {Weinstein, Steve},
            keywords = {Quantum Foundations},
            language = {en},
            title = {Decoherence and the (non)emergence of classicality.},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2008},
            month = {sep},
            note = {PIRSA:08090074 see, \url{https://scivideos.org/index.php/pirsa/08090074}}
          }
          

Abstract

It is widely believed that the dynamical mechanism of decoherence plays a key role in understanding the emergence of classicality from quantum systems, via the environment-induced superselection of a preferred set of subsystem states, the density matrices for which are approximately diagonal in the pointer basis. In this talk, I prove that the vast majority of subsystems do *not* exhibit this behavior, regardless of the Hamiltonian. This shows that the emergence of classicality is highly state-dependent (as suggested by related work of Hartle and others).