Classical and quantum Big Brake cosmology for scalar field and tachyonic models

TL;DR

This paper compares classical and quantum cosmological models with Big Brake singularities, showing quantum avoidance occurs only for strong singularities like Big Bang and Big Crunch, not for the soft Big Brake singularity.

Contribution

It demonstrates the differing quantum behaviors of soft and strong singularities in scalar and tachyonic cosmological models.

Findings

Quantum avoidance is absent for Big Brake singularities.

Quantum effects prevent traversal of Big Bang and Big Crunch singularities.

Soft singularities like Big Brake are traversable in quantum cosmology.

Abstract

We study a relation between the cosmological singularities in classical and quantum theory, comparing the classical and quantum dynamics in some models possessing the Big Brake singularity - the model based on a scalar field and two models based on a tachyon-pseudo-tachyon field . It is shown that the effect of quantum avoidance is absent for the soft singularities of the Big Brake type while it is present for the Big Bang and Big Crunch singularities. Thus, there is some kind of a classical - quantum correspondence, because soft singularities are traversable in classical cosmology, while the strong Big Bang and Big Crunch singularities are not traversable.