  In this paper we reconstruct the growth and evolution of the cosmic structure
of the Universe using Markov Chain Monte Carlo algorithms for Gaussian
processes [1]. We estimate the difference between the reconstructions that are
calculated through a maximization of the kernel hyperparameters and those that
are obtained with a complete exploration of the parameter space. We find that
the difference between these two approaches is of the order of $1\%$.
Furthermore, we compare our results with those obtained by Planck Collaboration
2018 assuming a $\Lambda$CDM model and we do not find a statistically
significant difference in the redshift range were the reconstructions of
$f\sigma_{8}$ have been made.
