Metastable dark energy

TL;DR

This paper proposes a metastable dark energy model based on a scalar potential with self-interactions, embedded in an $SU(2)_R$ symmetry, allowing for long-lived decay processes that connect dark energy and dark matter.

Contribution

It introduces a novel metastable dark energy framework with specific scalar potential interactions and explores its embedding in an $SU(2)_R$ symmetry, linking dark energy decay to dark matter interactions.

Findings

Decay time compatible with universe's age

Dark energy and dark matter interact via three-body decay

Model provides new insights into dark sector interactions

Abstract

We build a model of metastable dark energy, in which the observed vacuum energy is the value of the scalar potential at the false vacuum. The scalar potential is given by a sum of even self-interactions up to order six. The deviation from the Minkowski vacuum is due to a term suppressed by the Planck scale. The decay time of the metastable vacuum can easily accommodate a mean life time compatible with the age of the universe. The metastable dark energy is also embedded into a model with $SU(2)_R$ symmetry. The dark energy doublet and the dark matter doublet naturally interact with each other. A three-body decay of the dark energy particle into (cold and warm) dark matter can be as long as large fraction of the age of the universe, if the mediator is massive enough, the lower bound being at intermediate energy level some orders below the grand unification scale. Such a decay shows a different form of interaction between dark matter and dark energy, and the model opens a new window to investigate the dark sector from the point-of-view of particle physics.