Quantization of Friedmann cosmological models with two fluids: dust plus radiation

TL;DR

This paper applies the causal interpretation of quantum mechanics to homogeneous, isotropic quantum universes with dust and radiation, revealing bouncing behaviors and matter creation effects, with implications for quantum cosmology.

Contribution

It introduces a quantum cosmological model with dust and radiation, demonstrating bouncing universes and matter creation through non-unitary and unitary wave functions.

Findings

Bouncing quantum universes reaching classical limits.

Matter creation as a quantum effect in flat universes.

Wave functions without unitary evolution exhibit bouncing behavior.

Abstract

The causal interpretation of quantum mechanics is applied to a homogeneous and isotropic quantum universe, whose matter content is composed by non interacting dust and radiation. For wave functions which are eigenstates of the total dust mass operator, we find some bouncing quantum universes which reachs the classical limit for scale factors much larger than its minimum size. However these wave functions do not have unitary evolution. For wave functions which are not eigenstates of the dust total mass operator but do have unitary evolution, we show that, for flat spatial sections, matter can be created as a quantum effect in such a way that the universe can undergo a transition from an exotic matter dominated era to a matter dominated one.