Time Symmetry in Decoherence and Stable Facts

          @misc{ pirsa_PIRSA:21060121,
            doi = {10.48660/21060121},
            url = {https://pirsa.org/21060121},
            author = {Ganguly, Anirban},
            keywords = {Quantum Foundations},
            language = {en},
            title = {Time Symmetry in Decoherence and Stable Facts},
            publisher = {Perimeter Institute},
            year = {2021},
            month = {jun},
            note = {PIRSA:21060121 see, \url{https://pirsa.org}}
          }
          

Abstract

It has been previously discussed how events (interactions) in quantum mechanics are time-symmetric and an arrow of time is only due to the arrow of inference in the paper “Quantum information and the arrow of time”, arXiv:2010.05734 by Andrea Di Biagio, Pietro Dona, and Carlo Rovelli. In the relational interpretation of Quantum Mechanics, these interactions are relative facts. Stable facts result from relative facts through the process of decoherence as shown in the paper "Di Biagio, A., Rovelli, C., Foundations of Physics 51, 30 (2021)". They are separate from observed facts in laboratories due to the reason that they do not depend on a decision-making agent for their creation. In my talk, I will discuss my work with Carlo Rovelli and Andrea Di Biagio where we show that the process of decoherence and the notion of stability of facts is indeed time-symmetric. This is in contrast to the observed facts of our everyday world where an arrow of time emerges due to the presence of agents and traces.