Video URL

https://pirsa.org/19030120

Big bounce and inflation from spin and torsion

Poplawski, N. (2019). Big bounce and inflation from spin and torsion. Perimeter Institute for Theoretical Physics. https://pirsa.org/19030120

Poplawski, Nikodem. Big bounce and inflation from spin and torsion. Perimeter Institute for Theoretical Physics, Mar. 21, 2019, https://pirsa.org/19030120 

          @misc{ scivideos_PIRSA:19030120,
            doi = {10.48660/19030120},
            url = {https://pirsa.org/19030120},
            author = {Poplawski, Nikodem},
            keywords = {Strong Gravity},
            language = {en},
            title = {Big bounce and inflation from spin and torsion},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2019},
            month = {mar},
            note = {PIRSA:19030120 see, \url{https://scivideos.org/pirsa/19030120}}
          }

Nikodem Poplawski University of New Haven

DOI 10.48660/19030120
Source Repository PIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

The conservation law for the total (orbital plus spin) angular momentum of a Dirac particle in the presence of gravity requires that spacetime is not only curved, but also has a nonzero torsion. The coupling between the spin and torsion in the Einstein–Cartan theory of gravity generates gravitational repulsion at extremely high densities, which prevents a singularity in a black hole and may create there a new, closed, baby universe undergoing one or more nonsingular bounces. We show that quantum particle production caused by an extremely high curvature near a bounce creates enormous amounts of matter and can generate a finite period of inflation. Our scenario has only one parameter, does not depend significantly on the initial conditions, does not involve hypothetical scalar fields, avoids eternal inflation, and predicts plateau-like inflation that is supported by the Planck observations of the cosmic microwave background. This scenario suggests that our Universe may have originated from a nonsingular bounce in a black hole existing in another universe.