Rishabh Jha - Continuation through the Big Bang Singularity

Thursday 13 Jan 2022, 10:00 → 11:00 Europe/Berlin

Abstract: General relativity admits singular solutions, where the predictability of evolution of physical degrees of freedom is expected to break down. This notion is challenged by presenting classical solutions that satisfy existence and uniqueness theorems of differential equations at the big bang singularity, thereby surviving through it. This is presented for the class of homogeneous anisotropic cosmological models, namely the Bianchi IX universe, coupled to stiff matter sources such as scalar fields, using the ADM formalism of general relativity. The talk focuses on developing the prerequisites for this work, in particular the 3+1 decomposition of spacetime (& consequently the ADM formalism) as well as an introduction to the homogeneous universes. The talk will conclude by showing the results for the case of a scalar field minimally coupled to gravity whose classical solutions survive through the big bang singularity. Possible future directions will be mentioned.