Extended Inflation - a quantum cosmological survey

TL;DR

This paper investigates quantum cosmological models with Einstein-Brans-Dicke and Higgs sectors, analyzing classical exit from inflation, wormhole solutions, and the universe's wavefunction with arbitrary factor-ordering.

Contribution

It provides a detailed analysis rejecting classical graceful exit in this model, explores wormhole solutions, and constructs the universe's wavefunction for arbitrary factor-ordering.

Findings

Classical graceful exit from inflation is not possible in this model.

Wormhole solutions with and without conserved charges are identified.

The universe's wavefunction is constructed for any factor-ordering index.

Abstract

This paper considers Einstein-Brans-Dicke action being coupled with a Higgs sector. It is shown that classically graceful exit from inflation is not possible in principle, rejecting the claim of La and Steinhardt. Further, wormhole solutions with and without conserved charges are explored. Finally, the wavefunction of the universe in this model is constructed with the boundary condition, as proposed by Vilenkin. The interesting feature of the wavefunction is that it has been constructed for an arbitrary factor-ordering index.