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GR: Fachverband Gravitation und Relativitätstheorie
GR 3: Cosmology
GR 3.1: Talk
Monday, March 21, 2022, 16:15–16:35, GR-H3
Through the Big Bang — •Paula Reichert — Mathematisches Institut, LMU München, Germany
This talk presents latest results regarding the evolution of the universe through the Big Bang singularity on shape space. Relationalism in the form of modern shape dynamics suggests that the Big Bang is only a turning or Janus point within an overall time-symmetric, eternal evolution - a common past in a universe with one past (i.e. the Big Bang) and two futures in both directions away from it. This idea is supported by the 2016 result that, for the quiescent Bianchi IX model of GR, the shape (i.e. angular) degrees of freedom can be evolved uniquely through the (otherwise singular) point of zero spatial volume. Studies of the total collision singularity on non-relativistic shape space further suggest that, at the point of total collision (i.e. the Big Bang of the Newtonian N-body universe), the system is exceptionally homogenous, forming a state of minimal shape complexity and minimal entropy. At the same time, both complexity and entropy increase as the system expands and galaxies form in both directions away from the Janus point, thereby marking two gravitational and entropic arrows of time.