Running Vacuum in the Universe: current phenomenological status

Understand

I review the excellent phenomenological status of a class of dynamical vacuum models in which the vacuum energy density, $\rho_{\Lambda}=\rho_{\Lambda}(H)$, as a function of the Hubble rate, evolves through its interaction with dark matter and/or through the accompanying running of the gravitational coupling $G$, including the possibility of being self-conserved with a nontrivial effective equation of state.

• Some of these models have been used to incorporate into a single vacuum structure the rapid stage of inflation, followed by the standard radiation and cold dark matter epochs all the way down until the dark energy era.
• Remarkably, the running vacuum models (RVM's) render an outstanding phenomenological description of the main cosmological data at a level that is currently challenging the concordance $\Lambda$CDM model, thereby implying that present observations seem to point to a running vacuum rather than to a rigid cosmological constant $\Lambda$ in our Universe.