A Random Matrix Perspective of Echo State Networks: From Precise Bias--Variance Characterization to Optimal RegularizationYessin Moakher, Malik Tiomoko, Cosme Louart, Zhenyu Liaohttps://arxiv.org/abs/2509.22011
A Random Matrix Perspective of Echo State Networks: From Precise Bias--Variance Characterization to Optimal RegularizationWe present a rigorous asymptotic analysis of Echo State Networks (ESNs) in a teacher student setting with a linear teacher with oracle weights. Leveraging random matrix theory, we derive closed form expressions for the asymptotic bias, variance, and mean-squared error (MSE) as functions of the input statistics, the oracle vector, and the ridge regularization parameter. The analysis reveals two key departures from classical ridge regression: (i) ESNs do not exhibit double descent, and (ii) ESNs …