Cosmological Constant from Decoherence

TL;DR

This paper proposes a decoherence-based mechanism involving scalar fields and multiple potential wells to explain why the cosmological constant has a small positive value, linking quantum effects to dark energy.

Contribution

It introduces a novel decoherence approach with scalar fields in multiple wells to explain the small positive cosmological constant, extending previous landscape models.

Findings

Decoherence localizes the scalar field in one well, resulting in a small positive dark energy.

Additional degrees of freedom increase tunneling rates between wells.

The model is extended from two wells to many wells, supporting the mechanism's robustness.

Abstract

We address the issue why a cosmological constant (dark energy) possesses a small positive value instead of being zero. Motivated by the cosmic landscape picture, we mimic the dark energy by a scalar field with potential wells and show that other degrees of freedom interacting with it can localize this field by decoherence in one of the wells. Dark energy can then acquire a small positive value. We also show that the additional degrees of freedom enhance the tunneling rate between the wells. The consideration is performed in detail for the case of two wells and then extended to a large number of wells.