# Possible signals of vacuum dynamics in the Universe

## TL;DR

This paper investigates time-evolving vacuum models, especially the running vacuum model, which better fit cosmological data and may resolve tensions in the standard $\\Lambda$CDM model.

## Contribution

It demonstrates that dynamical vacuum models, particularly the RVM, are favored by current observations and provides a comparative analysis with other dark energy parametrizations.

## Key findings

- Running vacuum model is favored at ~3σ confidence level.
- Modern observations support the presence of vacuum dynamics.
- Without key data, signals of dynamical dark energy are not significant.

## Abstract

We study a generic class of time-evolving vacuum models which can provide a better phenomenological account of the overall cosmological observations as compared to the $\Lambda$CDM. Among these models, the running vacuum model (RVM) appears to be the most motivated and favored one, at a confidence level of $\sim 3\sigma$. We further support these results by computing the Akaike and Bayesian information criteria. Our analysis also shows that we can extract fair signals of dynamical dark energy (DDE) by confronting the same set of data to the generic XCDM and CPL parametrizations. In all cases we confirm that the combined triad of modern observations on Baryonic Acoustic Oscillations, Large Scale Structure formation, and the Cosmic Microwave Background, provide the bulk of the signal sustaining a possible vacuum dynamics. In the absence of any of these three crucial data sources, the DDE signal can not be perceived at a significant confidence level. Its possible existence could be a cure for some of the tensions existing in the $\Lambda$CDM when confronted to observations.