# On the effect of renormalization group improvement on the cosmological power spectrum

## TL;DR

This paper explores how asymptotically safe quantum gravity, with its running couplings and fixed points, influences cosmological perturbations and the resulting power spectrum, by deriving and solving an improved perturbation equation.

## Contribution

It introduces an improved Mukhanov-Sassaki equation incorporating quantum gravity effects and analyzes their impact on the cosmological power spectrum.

## Key findings

- Quantum gravity effects modify the cosmological power spectrum.
- Derived an improved perturbation equation accounting for running couplings.
- Studied two models to assess the impact of asymptotic safety on cosmological fluctuations.

## Abstract

Asymptotically safe quantum gravity predicts running gravitational and cosmological constants, while it remains a meaningful quantum field theory because of the existence of non-Gaussian ultraviolet fixed points. Here we have investigated the effect of such running couplings on the cosmological perturbations. We have obtained the improved Mukhanov-Sassaki equation and solved it for two models. The effect of asymptotically safe quantum gravity on the cosmological power spectrum is also studied.