EN
We establish functional type inequalities linking the regularity properties of sequences of operators S = (Sₙ) acting on L²-spaces with those of the canonical Gaussian process on the associated subsets of L² defined by (Sₙ(f)), f ∈ L². These inequalities allow us to easily deduce as corollaries Bourgain's famous entropy criteria in the theory of almost everywhere convergence. They also provide a better understanding of the role of the Gaussian processes in the study of almost everywhere convergence. A partial converse path to Bourgain's entropy criteria is also proposed.