Exact solutions of the Wheeler-DeWitt equation with ordering term in a dark energy scenario

Abstract

We investigate the quantum evolution of the universe in the presence of two types of dark energies. First, we consider the phantom class ($\omega <-1$) which would be responsible for a super-accelerated cosmic expansion, and then we apply the procedure to an ordinary $\Lambda >0$ vacuum ($\omega =-1$). This is done by analytically solving the Wheeler-DeWitt equation with ordering term (WdW) in the cosmology of Friedmann-Robertson-Walker. In this paper, we find exact solutions in the scale factor $a$ and the ordering parameter $q$. For $q=1$ it is shown that the universe has a high probability of evolving from a big bang singularity. On the other hand, for $q=0$ the solution indicates that an initial singularity is unlikely. Instead, the universe has maximal probability of starting with a finite well-defined size which we compute explicitly at primordial times. We also study the time evolution of the scale factor by means of the Hamilton-Jacobi equation and show that an ultimate big rip singularity emerges explicitly from our solutions. The phantom scenario thus predicts a dramatic end in which the universe would reach an infinite scale factor in a finite cosmological time as pointed by Caldwell et al. in a classical setup. Finally, we solve the WdW equation with ordinary constant dark energy and show that in this case the universe does not rip apart in a finite era.

16 pages, improved figures, some new relevant conclusions, references added

References in corpus (6)

• Why the cosmological constant is small and positive
• Hiding the cosmological constant
• Casimir Effect in the Kerr Spacetime with Quintessence
• Vacuum fluctuation, micro-cyclic "universes" and the cosmological constant problem
• Thermal Casimir effect in Kerr spacetime with quintessence and massive gravitons
• The Day the Universes Interacted: Quantum Cosmology without a Wave function

Cited by in corpus (1)

• Class of solutions of the Wheeler-DeWitt equation with ordering parameter