From Asymptotic Safety to Dark Energy

TL;DR

This paper explores how renormalization group flow influences cosmological models with dark energy, identifying fixed points that describe different universe evolutions and linking quantum gravity concepts to cosmic acceleration.

Contribution

It introduces a framework connecting RG flow parameters with cosmological evolution, revealing fixed points that describe various dark energy scenarios and their relation to asymptotic safety.

Findings

Identified three classes of cosmological fixed points involving dark energy and fluids.

Found conditions under which dark energy dominates or fades away.

Linked IR fixed points with the Hubble scale in de Sitter solutions.

Abstract

We consider renormalization group flow applied to the cosmological dynamical equations. A consistency condition arising from energy-momentum conservation links the flow parameters to the cosmological evolution, restricting possible behaviors. Three classes of cosmological fixed points for dark energy plus a barotropic fluid are found: a dark energy dominated universe, which can be either accelerating or decelerating depending on the RG flow parameters, a barotropic dominated universe where dark energy fades away, and solutions where the gravitational and potential couplings cease to flow. If the IR fixed point coincides with the asymptotically safe UV fixed point then the dark energy pressure vanishes in the first class, while (only) in the de Sitter limit of the third class the RG cutoff scale becomes the Hubble scale.