arXiv AI By Arthur C. B. de Oliveira, Dhruv D. Jatkar, Guilherme S. Vicinansa, Eduardo D. Sontag

Convergence guarantees for Muon: New parameter regimes and generalizations

Read the original on arXiv AI →

The paper presents the first asymptotic convergence guarantees for the Muon algorithm, showing that with suitable hyperparameters the iterates satisfy ≠≠ ∥∇f(x_k)∥ → 0 and, under a global Polyak-ℒojasiewicz condition, the function values converge linearly. It reveals that Muon’s implicit regularization acts as a bounded preconditioner, framing Muon as a preconditioned Polyak heavy‑ball method and enabling a Lyapunov analysis. Building on this insight, the authors introduce Muesterov, a Nesterov‑based variant, and prove it shares the same convergence guarantees, extending the theory beyond the heavy‑ball setting; numerical experiments on a scalar cross‑entropy problem and preliminary nanoGPT simulations support the theoretical findings.

Machine-generated by The Flow from the publisher's headline and feed description — not written or checked by a human. The full article lives at arXiv AI.

arXiv Machine Learning
Aug 28

Muon with Finite Newton-Schulz: The Smoothing Benefit in Nonsmooth Nonconvex Optimization

The paper introduces Muon, an optimizer that uses a finite number of Newton‑Schulz iterations to approximate the polar factor for matrix‑valued parameters in large language model pretraining. It demonstrates that this finite iteration smooths the discontinuous polar map into a Lipschitz function of singular values, enabling a conversion from online learning regret to a stationarity guarantee in nonsmooth nonconvex optimization. The authors prove that a logarithmic depth in Newton‑Schulz suffices for convergence to stationary points, matching best‑known sample complexity bounds and extending the result to other spectral maps with similar smoothing properties.

By Mingyi Li, Taira Tsuchiya