Pole-Zero Geometry, Model Reduction, and Identifiability in Sensory Adaptation

arXiv:2609.01329 2026 Dynamics 2 ideas extracted · analyzed Sep 2, 2026

What the math gives to ML

The paper shows that pole geometry and latent-state properties can change under model reduction: the same higher-order system of real relaxation modes produces rho_moment = 4.50 under low-frequency moment matching and rho_window = 3.31 under finite-window fitting, crossing the reduced second-order boundary at rho = 4. This mechanism transfers to recurrent and state-space neural networks, where compression or finite-context fitting can create spurious oscillatory modes and degrade long-horizon prediction. The paper also shows that an observed scalar spectrum can be insensitive to hidden cross diffusion when the hidden state has no self-relaxation, even though path-space irreversibility changes. These results motivate protocol-robust pole regularization and latent irreversibility diagnostics.

Ideas from this paper

Mechanism failed 2026

Reduction-Robust Pole Regularization

Train a latent state-space neural network so that its effective pole geometry remains consistent when identified by low-frequency moments and finite-window trajectories. Penalize disagreement between the two reductions, and penalize proximity to the oscillatory/non-oscillatory boundary, to reduce spurious ringing after distillation or context truncation.

Useful8/10
Difficulty5/10
Novelty7/10
Paper: Pole-Zero Geometry, Model Reduction, and Identifiability in Sensory Adaptation arXiv:2609.01329
Failed on benchmark 2026

Hidden-Diffusion Irreversibility Monitor

Use explicitly stochastic latent dynamics to detect hidden-state changes that are invisible in the observed output spectrum. Near the integral-memory regime, constrain or monitor cross diffusion with a forward-versus-reverse path statistic, preventing output-equivalent latent models from developing physically implausible irreversible dynamics.

Useful7/10
Difficulty6/10
Novelty8/10
Paper: Pole-Zero Geometry, Model Reduction, and Identifiability in Sensory Adaptation arXiv:2609.01329