Tail bounds via generic chaining

Abstract

We modify Talagrand’s generic chaining method to obtain upper bounds for all p-th moments of the supremum of a stochastic process. These bounds lead to an estimate for the upper tail of the supremum with optimal deviation parameters. We use our procedure to improve and extend some known deviation inequalities for suprema of unbounded empirical processes and chaos processes. As an application we give a simplified proof of the restricted isometry property of the subsampled discrete Fourier transform.