Physical Aspects of Unitary evolution of Bianchi-I Quantum Cosmological Model

Abstract

In this work, we study some physical aspects of unitary evolution of Bianchi-I model. In particular, we study the behavior of the volume and the scale factor as a function of time for the Bianchi-I universe with ultra-relativistic fluid ($\alpha=1$). The expectation value of volume is shown not to hit any singularity. We elucidate on the anisotropic nature of the solution and physically interpret the wavefunction as a superposition of collapsing universe and expanding universe mimicking Hartle-Hawking type wavefunction. The same analysis has been done for $\alpha\neq 1$ as well. The work also comments on how to obtain Vilenkin type wavefunction representing an expanding universe without that being superposed with a solution representing a collapsing universe. We also point at a possible phase transition phenomenon for $\alpha\neq1$ case with existence of a critical parameter.