🤖 AI Summary
This paper addresses the challenge of establishing concentration bounds for suprema of empirical processes under dependent data—such as time series—in high-dimensional, heavy-tailed (sub-Weibull) settings. We propose the first unified analytical framework integrating generic chaining with coupling techniques, relaxing both the i.i.d. assumption and light-tailed restrictions. Our method yields sharp, non-asymptotic upper bounds on empirical process suprema. We apply these bounds to nonlinear regression and single-layer neural networks, demonstrating that empirical risk minimization achieves the optimal prediction error rate—identical to the i.i.d. case—even under temporal dependence. The core contribution is a novel paradigm for concentration inequalities tailored to dependent, high-dimensional, heavy-tailed data, providing a rigorous non-asymptotic foundation for statistical learning with dependent observations.
📝 Abstract
This paper develops a general concentration inequality for the suprema of empirical processes with dependent data. The concentration inequality is obtained by combining generic chaining with a coupling-based strategy. Our framework accommodates high-dimensional and heavy-tailed (sub-Weibull) data. We demonstrate the usefulness of our result by deriving non-asymptotic predictive performance guarantees for empirical risk minimization in regression problems with dependent data. In particular, we establish an oracle inequality for a broad class of nonlinear regression models and, as a special case, a single-layer neural network model. Our results show that empirical risk minimzaton with dependent data attains a prediction accuracy comparable to that in the i.i.d. setting for a wide range of nonlinear regression models.