Exact renormalization group with optimal scale and its application to cosmology

TL;DR

This paper develops an exact renormalization group method with an optimal scale choice, applying it to cosmology to analyze scale-dependent gravitational couplings and derive bounds on ultraviolet fixed points.

Contribution

It introduces a consistency condition for the cutoff scale and applies it to cosmology, providing new insights into fixed point bounds in quantum gravity.

Findings

Derived bounds on the ultraviolet fixed point value.

Established a consistency condition for the local cutoff scale.

Applied the approach to homogeneous cosmology with running couplings.

Abstract

Assuming an effective gravitational action with scale dependent coupling constants, a consistency condition for the local form of the cut-off scale is derived. The approach is applied to homogeneous cosmology and running couplings with an ultraviolet fixed point. Within the given approach this allows to derive bounds on the value of the fixed point.