Running vacuum versus the $\Lambda$CDM

TL;DR

This paper demonstrates that running vacuum models, possibly with a variable gravitational constant, can fit cosmological data better than the standard Lambda-CDM model, suggesting they may be a more optimal description of the universe.

Contribution

It introduces and tests running vacuum models with variable G, showing they outperform Lambda-CDM in fitting cosmological observations with strong statistical support.

Findings

Running vacuum models fit data better than Lambda-CDM at ~3σ level.

Statistical criteria favor running vacuum models over Lambda-CDM.

Possible variation of G improves model fit.

Abstract

It is well-known that a constant $\Lambda$-term is a traditional building block of the concordance $\Lambda$CDM model. We show that this assumption is not necessarily the optimal one from the phenomenological point of view. The class of running vacuum models, with a possible running of the gravitational coupling G, are capable to fit the overall cosmological data SNIa+BAO+H(z)+LSS+BBN+CMB better than the $\Lambda$CDM, namely at a level of $\sim 3\sigma$ and with Akaike and Bayesian information criteria supporting a strong level of statistical evidence on this fact. Here we report on the results of such analysis.