Liouville Decoherence in a Model of Flavour Oscillations in the presence of Dark Energy

TL;DR

This paper investigates how dark energy and space-time defects influence quantum decoherence and flavour oscillations in a two-level system, highlighting the role of a cosmological constant in quantum damping effects.

Contribution

It provides a detailed analysis of the master equation in a Liouville-string model, contrasting the effects of dark energy and space-time foam on quantum decoherence.

Findings

Dark energy induces exponential damping of flavour oscillations.

Decoherence effects depend on whether dark energy relaxes to zero.

The model suggests potential astrophysical tests of quantum space-time foam.

Abstract

We study in some detail the master equation, and its solution in a simplified case modelling flavour oscillations of a two-level system, stemming from the Liouville-string approach to quantum space time foam. In this framework we discuss the appearance of diffusion terms and decoherence due to the interaction of low-energy string matter with space-time defects, such as D-particles in the specific model of ``D-particle foam'', as well as dark energy contributions. We pay particular attention to contrasting the decoherent role of a cosmological constant in inducing exponential quantum damping in the evolution of low-energy observables, such as the probability of flavour oscillations, with the situation where the dark energy relaxes to zero for asymptotically large times, in which case such a damping is absent. Our findings may be of interest to (astrophysical) tests of quantum space-time foam models in the not-so-distant future.