Stability Issues for w < -1 Dark Energy

TL;DR

This paper examines the stability of dark energy with an equation of state less than -1, suggesting that such a state is stable due to extremely slow nucleation rates of phase transitions, making it consistent with cosmological observations.

Contribution

It provides a theoretical analysis of the stability of w < -1 dark energy by evaluating nucleation processes and their implications for cosmic stability.

Findings

Nucleation from positive to zero cosmological constant is possible but highly suppressed.

Critical radius for phase transition is at least galactic scale.

Nucleation rate is extremely slow, supporting dark energy stability.

Abstract

Precision cosmological data hint that a dark energy with equation of state $w = P/\rho < -1$ and hence dubious stability is viable. Here we discuss for any $w$ nucleation from $\Lambda > 0$ to $\Lambda = 0$ in a first-order phase transition. The critical radius is argued to be at least of galactic size and the corresponding nucleation rate is glacial, thus underwriting the dark energy's stability and rendering remote any microscopic effect.