Causality, Time Arrow and Half Cycling Universe

TL;DR

This paper explores how introducing causality into quantum cosmology affects the no-boundary universe, revealing a reversal of the thermodynamic arrow of time at maximum expansion, leading to a universe that terminates after half a cycle.

Contribution

It proposes a revision to the no-boundary universe prescription by incorporating causality, showing the reversal of the thermodynamic arrow of time in an oscillating Hawking model.

Findings

Thermodynamic arrow of time reverses at maximum expansion.

Universe terminates after half a cycle in the model.

Causality impacts the evolution of quantum cosmological models.

Abstract

If one introduces causality into quantum cosmology, then the prescription for the no-boundary universe should be revised. We show that the thermodymanic arrow of time associated with the perturbation modes should be reversed at the maximum expansion for the oscillating Hawking model. To an observer equipped with the time arrow, the universe will terminate its evolution after an half cycle.