Thermodynamic natural gradient descent (NGD-T) regulates natural-gradient steps by a geometric speed-cost bound
摘要
We introduce Thermodynamic Natural Gradient Descent (NGD-T), an optimizer that enforces a physical speed-cost constraint by combining Fisher-preconditioned updates with a dissipation-aware step-size regulator. While natural gradient methods are known to follow the steepest descent direction in information geometry, we provide a thermodynamic reinterpretation: Natural Gradient Flow uniquely minimizes instantaneous irreversible dissipation for a fixed loss decrease. NGD-T implements this principle in discrete updates by (i) preconditioning gradients with an approximate inverse Fisher, (ii) computing the geometric norm