Constraining the Swiss-Cheese IR-Fixed Point Cosmology with Cosmic Expansion

Abstract

A recent work proposed that the recent cosmic passage to a cosmic acceleration era is the result of the existence of small anti-gravity sources in each galaxy and clusters of galaxies. In particular, a Swiss-cheese cosmology model, which relativistically integrates the contribution of all these anti-gravity sources on a galactic scale has been constructed assuming the presence of an infrared fixed point for a scale dependent cosmological constant. The derived cosmological expansion provides an explanation for both the fine tuning and the coincidence problem. The present work relaxes the previous assumption on the running of the cosmological constant and allows for a generic scaling around the infrared fixed point. Our analysis reveals that, in order to produce a cosmic evolution consistent with the best ΛCDM model, the IR-running of the cosmological constant is consistent with the presence of an IR-fixed point.

Swiss-cheese cosmologies with variable G and Λ from the renormalization group

“…Therefore in our numerical assessments we set h 1 ¼ G N and assume that θ 1 must be close to 2. On the other hand, as it has already been proven that a term proportional to k 2 , generates successful phenomenology [31][32][33] we also assume that θ 2 must be close to 0, and since both terms are practically proportional to k 2 , we can choose λ Ã ≪ 1. We further simplify our search for a viable cosmological model assuming…”

Swiss-cheese cosmologies with variable $G$ and $Λ$ from the renormalization group

“…Therefore in our numerical assessments we set h 1 = G N and assume that θ 1 must be close to 2. On the other hand, as it has already been proven that a term proportional to k 2 , generates successful phenomenology [31][32][33] we also assume that θ 2 must be close to 0, and since both terms are practically proportional to k 2 , we can choose λ * 1. We further simplify our search for a viable cosmological model assuming…”

“…The basic idea is to consider the contribution of an homogeneous distribution of antigravity sources associated with the matter content at galactic and cluster scale. A swiss-cheese cosmology represents an elegant mathematical framework to implement this idea which has been elaborated also in [31][32][33]. In this work we would like to extend the original RG-improved swiss-cheese model to include the running of the Newton's constant according to the IR-fixed point mechanism.…”

Asymptotic Safety and the Cosmic Coincidence Problem

“…In the latter case AS can explain the recent cosmological constant problem but with fine tuning and without answering about the coincidence problem. However, AS may explain both old and new cosmological constant, as well as the coincidence problem without fine tuning with the AS swiss model first proposed in [6] and further studied and generalised in [9], [10], [8], [7].…”

“…Furthermore, results from a series of papers concerning AS swiss cheese model with an interesting solution of the dark energy problem will be given. [6], [7], [8], [9], [10]. Finally, focusing again on the dark energy model the low energy cosmic evolution of recently developed minimally modified Einstein equations compatible with AS gravity, [11], will be given for the first time.…”