An emergent cosmological model from running Newton constant

TL;DR

This paper introduces a cosmological model based on the scale-dependent behavior of Newton's constant, derived from Asymptotic Safety, which transitions from a quasi-de Sitter phase to standard cosmology and can be tested with CMB data.

Contribution

It presents a novel emergent cosmological model incorporating a running Newton constant with a conserved energy-momentum tensor, distinct from previous models.

Findings

Feasibility of constraining the transition scale using CMB data

Demonstration of empirical probes for antiscreening of Newton's constant

Model aligns with standard cosmology post-Planck era

Abstract

We propose an emergent cosmological model rooted in the Asymptotically Safe antiscreening behavior of the Newton constant at Planckian energies. Distinguishing itself from prior approaches, our model encapsulates the variable nature of $G$ through a multiplicative coupling within the matter Lagrangian, characterized by a conserved energy-momentum tensor. The universe emerges from a quasi-de Sitter phase, transitioning to standard cosmological evolution post-Planck Era. Our analysis demonstrates the feasibility of constraining the transition scale to nearly classical cosmology using Cosmic Microwave Background (CMB) data and the potential to empirically probe the antiscreening trait of Newton's constant, as predicted by Asymptotic Safety.