PIRSA:19110052

Video URL

https://pirsa.org/19110052

Planckian discreteness as a solution of Hawking's information puzzle

Perez, A. (2019). Planckian discreteness as a solution of Hawking's information puzzle. Perimeter Institute for Theoretical Physics. https://pirsa.org/19110052

Perez, Alejandro. Planckian discreteness as a solution of Hawking's information puzzle. Perimeter Institute for Theoretical Physics, Nov. 15, 2019, https://pirsa.org/19110052 

          @misc{ scivideos_PIRSA:19110052,
            doi = {10.48660/19110052},
            url = {https://pirsa.org/19110052},
            author = {Perez, Alejandro},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Planckian discreteness as a solution of  Hawking{\textquoteright}s information puzzle},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2019},
            month = {nov},
            note = {PIRSA:19110052 see, \url{https://scivideos.org/pirsa/19110052}}
          }

Alejandro Perez Aix-Marseille University

Talk numberPIRSA:19110052
DOI10.48660/19110052
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

In approaches to quantum gravity, where smooth spacetime is an emergent approximation of a discrete Planckian fundamental structure, any standard effective field theoretical description will miss part of the degrees of freedom and thus break unitarity. Here we show that these expectations can be made precise in loop quantum cosmology. Concretely, even when loop quantum cosmology is unitary at the fundamental level, when microscopic degrees of freedom, irrelevant to low-energy cosmological observers, are suitably ignored, pure states in the effective description evolve into mixed states due to decoherence with the Planckian microscopic structure. When extrapolated to black hole formation and evaporation, this concrete example provides a key physical insight for a natural resolution of Hawking's information paradox.