Chaos, decoherence and quantum cosmology

TL;DR

This review explores the interplay between chaos, decoherence, and quantum cosmology, emphasizing the role of decoherence in interpreting the wave function of the universe, while highlighting gaps in understanding semiclassical transitions in chaotic models.

Contribution

It synthesizes existing knowledge on chaos and decoherence in quantum cosmology and identifies the need for further research on semiclassical transitions in chaotic cosmological models.

Findings

Decoherence is crucial for interpreting the wave function of the universe.

A comprehensive account of semiclassical transition in chaotic models is lacking.

Decoherence may be sufficient for a consistent quantum cosmological interpretation.

Abstract

In this topical review we discuss the connections between chaos, decoherence and quantum cosmology. We understand chaos as classical chaos in systems with a finite number of degrees of freedom, decoherence as environment induced decoherence and quantum cosmology as the theory of the Wheeler - DeWitt equation or else the consistent history formulation thereof, first in mini super spaces and later through its extension to midi super spaces. The overall conclusion is that consideration of decoherence is necessary (and probably sufficient) to sustain an interpretation of quantum cosmology based on the Wave function of the Universe adopting a Wentzel - Kramers - Brillouin form for large Universes, but a definitive account of the semiclassical transition in classically chaotic cosmological models is not available in the literature yet.