Decay of Correlations for Partially Hyperbolic Skew-Products

arXiv:2607.21516 2026 Dynamics 1 ideas extracted · analyzed Aug 30, 2026

What the math gives to ML

The paper develops a sectional transfer-operator framework for skew-products whose fibre dynamics contract only in an averaged logarithmic sense. Its main transferable mechanism is that pointwise contraction is unnecessary: a negative mean log-Lipschitz rate can still produce a unique invariant section, forgetting of fibre initialization, and exponential statistical control. In neural networks, this suggests separating an expressive base state from an input-conditioned auxiliary fibre state and regularizing only the fibre's average log-Jacobian gain. The key falsifiable prediction is a sharp stability transition when the measured average log gain crosses zero, with exponential perturbation decay below that boundary.

Ideas from this paper

Failed on benchmark 2026

Average-contracting invariant fibre

Replace pointwise spectral-norm contraction in a recurrent or state-space model with an average logarithmic contraction certificate for an input-conditioned fibre update. Let a base state carry expressive, possibly noncontractive dynamics, while an auxiliary latent fibre contracts on average. This should preserve useful variability in the base while preventing long-horizon fibre explosion and making the fibre converge to an input-dependent invariant section.

Useful8/10
Difficulty5/10
Novelty7/10
Paper: Decay of Correlations for Partially Hyperbolic Skew-Products arXiv:2607.21516