# Observational constraints on running vacuum model

## TL;DR

This paper tests the running vacuum model against cosmological data, constraining its parameters and comparing its fit to the standard Lambda Cold Dark Matter model, finding it slightly better.

## Contribution

It provides observational constraints on the running vacuum model's parameter bd and compares its fit to the bLambda CDM model using CMB and matter power spectra.

## Key findings

- bd b1 1.54 imes 10^{-4} at 68% CL
- RVM fits data slightly better than bLambda CDM
- Best-fit bchi^2 b0 13968.8

## Abstract

We investigate the power spectra of the CMB temperature and matter density in the running vacuum model (RVM) with the time-dependent cosmological constant of $\Lambda = 3 \nu H^2 + \Lambda_0$, where $H$ is the Hubble parameter. In this model, dark energy decreases in time and decays to both matter and radiation. By using the Markov chain Monte Carlo method, we constrain the model parameter $\nu$ as well as the cosmological observables. Explicitly, we obtain $\nu \leq 1.54 \times 10^{-4}$ (68\% confidence level) in the RVM with the best-fit $\chi^2_{\mathrm{RVM}} = 13968.8$, which is slightly smaller than $\chi^2_{\Lambda \mathrm{CDM}} = 13969.8$ in the $\Lambda$CDM model of $\nu=0$.