Equivalence classes of finite-time transitions in optimal control and non-equilibrium relaxation

arXiv:2609.03862 2026 Dynamics 1 ideas extracted · analyzed Sep 4, 2026

What the math gives to ML

The paper provides a constructive classification of finite-horizon stochastic optimal-control problems by the sign of the determinant of a Hamiltonian matrix, yielding parabolic, hyperbolic, and elliptic control regimes. Its transferable asset is the prediction that finite training horizons can cross a computable conjugate-point or bifurcation time at which the optimal trajectory changes qualitatively, rather than merely degrading smoothly. A practical neural-network adaptation is a mode-wise Hamiltonian optimizer that estimates local curvature and damping, computes the corresponding finite-horizon Riccati flow, and changes the horizon or learning-rate policy before the predicted singularity. The mechanism is falsifiable through a sharp divergence or mode-switch boundary in the optimizer gain as the horizon crosses the calculated critical time.

Ideas from this paper

Unverified 2026

Hamiltonian Horizon-Critical Optimizer

Replace a fixed first-order parameter update by a finite-horizon controlled local model for each important curvature mode of the network. The optimizer computes the Hamiltonian flow and its Riccati feedback gain; if the chosen horizon approaches a conjugate point, it shortens the horizon or increases control cost before the gain becomes singular. This converts the paper's finite-time transition into a measurable trust-region and scheduling mechanism for neural training.

Useful8/10
Difficulty6/10
Novelty8/10
Paper: Equivalence classes of finite-time transitions in optimal control and non-equilibrium relaxation arXiv:2609.03862