Dynamical Dark Energy Emerges from Massive Gravity

TL;DR

This paper shows that massive gravity can produce a dynamic dark energy component with distinctive evolution, fitting current data better than the standard model and predicting testable deviations at high redshift.

Contribution

It introduces a self-consistent massive gravity model that naturally explains phantom dark energy and a small cosmological constant, with specific observational predictions.

Findings

Favored over ΛCDM by current datasets

Predicts a graviton mass around 4.0×10^{-33} eV

Suggests deviations in the equation of state at z~3

Abstract

In this work, we demonstrate that a dynamical dark energy component predicted by massive gravity gives rise to a distinctive evolution of the equation of state. This scenario is favoured over the standard $\Lambda$CDM model when confronted with the latest combined datasets from the Dark Energy Spectroscopic Instrument (DESI), the cosmic microwave background (CMB), and supernova observations. The model stands out as a rare example of a healthy, self-consistent theory that accommodates phantom dark energy while maintaining a technically natural, small asymptotic cosmological constant. Our analysis indicates a preferred graviton mass of approximately $4.0 \times 10^{-33} \text{eV}$, suggesting the emergence of a new cosmological length scale. This leads to a maximal deviation of the equation of state around $z \sim 3$, a prediction that will be robustly tested by upcoming, deeper surveys of baryon acoustic oscillations.