Tunneling of the Closed Friedmann Universe with Generation of Scalar Waves

TL;DR

This paper investigates how short scalar waves evolve during the tunneling process of a closed Friedmann Universe, revealing potential catastrophic amplification and a self-consistent mechanism for transitioning from quantum to classical states.

Contribution

It introduces a self-consistent approach to analyze scalar wave amplification during universe tunneling, extending previous models by considering back-reaction effects.

Findings

Short scalar waves can be catastrophically amplified during tunneling.

Back-reaction effects can reduce the barrier and halt wave amplification.

The model describes a transition from quantum tunneling to classical universe evolution.

Abstract

The evolution of the closed Friedmann Universe with a packet of short scalar waves is considered with the help of the Wheeler--DeWitt equation. The packet ensures conservation of homogeneity and isotropy of the metric on average. It is shown that during tunneling the amplitudes of short waves of a scalar field can increase catastrophically promptly if their influence to the metric do not take into account. This effect is similar to the Rubakov-effect of catastrophic particle creation calculated already in 1984. In our approach to the problem it is possible to consider self-consistent dynamics of the expansion of the Universe and amplification of short waves. It results in a decrease of the barrier and interruption of amplification of waves, and we get an exit of the wave function from the quantum to the classically available region.