10¹²⁰ is an abyss. That's how many times the density of dark energy is smaller than the natural quantum density. The reason for this tiny value is a mystery.
The new model offers an answer that's theatrical. It has an actor — a Goldstone boson (a massless particle born from symmetry breaking). In the first moments after the big bang, the universe inflated at enormous speed. This is inflation. During this time, our actor froze on stage. A conserved quantity (Noether current) kept it from moving. It remained motionless for billions of years, while matter dominated the universe.
The thaw begins later. A special version of gravity enters the scene — unimodular gravity. In it, spacetime curvature adjusts so that our particle finds a gentle slope. It starts to roll slowly. This motion is dark energy. The equation of state w0 comes out around −0,992 instead of exactly −1. The thaw speed parameter wa ≈ −0,011. Numerical simulations match these numbers beautifully, along with data from supernova and the cosmic microwave background.
The model’s key achievement is a predicted connection. The way the actor froze determined the pace of its awakening. Telescopes like Euclid, DESI, and the Rubin Observatory will measure the expansion of the universe and galactic redshift with high precision. If the acceleration matches the prediction, it will confirm the unified symmetry. A tiny thaw after an eternal freeze. Our dormant actor finally reveals the script of the whole cosmic history.
The Goldstone boson normally stays massless, but unimodular gravity gives it a tiny energy — about 10⁻¹²⁰ of the Planck density. That’s one of the smallest numbers in physics.
The paper includes an ironic nod to Star Wars: "That’s not how the Force works!"—because this boson doesn’t produce an observable fifth force.