Beyond the big bang in Loop Quantum Cosmology

          @misc{ scivideos_PIRSA:08060170,
            doi = {10.48660/08060170},
            url = {https://pirsa.org/08060170},
            author = {Singh, Parampreet},
            keywords = {Quantum Fields and Strings, Particle Physics, Cosmology},
            language = {en},
            title = {Beyond the big bang in Loop Quantum Cosmology },
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2008},
            month = {jun},
            note = {PIRSA:08060170 see, \url{https://scivideos.org/pirsa/08060170}}
          }
          

Abstract

Loop quantum cosmology is a non-perturbative canonical quantization of simple cosmological models based on loop quantum gravity. In recent years, a greater control on the underlying quantum theory has revealed a picture where the big bang is replaced by a quantum bounce at Planck scale. The evolution across the bounce is unitary and non-singular without a need of choice of exotic potential or matter. By analysis of an exactly solvable model of a homogeneous and isotropic spacetime we will describe how the backward evolution of our universe with the quantum constraint leads to a pre big bang branch. We will also discuss the way it predicts modifications to Friedman dynamics at high curvatures, contrasts with the Wheeler-DeWitt scenario and semi-classicality across the bounce.