arXiv Machine Learning

Conservation laws determine what physical learning remembers

arXiv:2608. 00097v1 Announce Type: cross Abstract: Physical learning rules such as equilibrium propagation (EP), coupled learning (CL), and adjoint coupled learning (AL) train resistive networks through local measurements.

arXiv AI
Aug 20

Untrainable elements determine what physical learning remembers

The paper investigates how two independent inductive biases—one from the circuit’s invariance under conductance rescaling and one from the learning rule’s conservation of a mass quantity—affect what a physical learning system remembers. By separating these effects, the authors show that when every element is trainable, the initialization scale has negligible influence on the learned function, whereas a single untrainable element can cause the function to shift significantly with initialization. They further demonstrate that the conservation law does not protect memory but instead influences solution quality, with adjoint coupled learning (AL) generally performing worse than equilibrium propagation (EP) and coupled learning (CL) in small circuits. whyItMatters":"The study clarifies that only the circuit’s structural bias, not the rule’s conservation property, determines memory retention in physical learning systems."

By Bijaya Dangol
arXiv Machine Learning
Jun 16

A Conservation Law for Equilibrium Propagation and Coupled Learning

arXiv:2606. 15444v1 Announce Type: cross Abstract: In this paper we show that the physical learning methods known as coupled learning (CL) and equilibrium propagation (EP) conserve a mass-like quantity in the trainable parameters in the continuous-time, small-nudging limit.

By Joshua A. McGinnis, Adam G. Kline, Yoichiro Mori
arXiv Machine Learning
Sep 18

Conservation Buys Stability and Factoring Buys Counterfactuals in Physical World Models

The paper demonstrates that learned simulators can fail in two distinct ways when conditions change: long‑horizon drift due to accumulated errors and incorrect responses to interventions on physical parameters. By adding a symplectic integrator to preserve conservative dynamics, rollouts remain stable for up to 100× the training horizon, while encoding physical coupling via explicit linear factorization allows the model to generalize to unseen signs of that coupling. The study shows that stability and counterfactual generalization arise from separate structural choices, enabling designers to impose each property independently.

By Yufeng Wang, Parivesh Priye, Lu Wei, Haibin Ling
arXiv Machine Learning
1d ago

Stable and Counterfactually Robust Physical World Models from Imposed Structure and Learned Physics

The paper introduces a world model that learns to predict the evolution of physical systems while respecting key physical principles. By hard‑coding a general structure—generating dynamics from the gradient of a learned energy via a fixed reversible operator and imposing constraints on energy, dissipation, and interventions—the model achieves second‑law compatible dissipation, accurate responses to parameter changes, long‑term stability, and robustness to disturbances. Experiments on an electromagnetic cavity, a particle‑in‑cell grid, and shallow‑water fluid demonstrate that the model can recover accurate constitutive functions, distinguish conserving from dissipating regimes, and transfer learned physics to unseen conditions, outperforming unconstrained models.

By Yufeng Wang, Parivesh Priye, Lu Wei, Haibin Ling