English

Dimension-Free Saddle-Point Escape in Muon

Machine Learning 2026-05-12 v1

Abstract

Modern Large Language Model (LLM) training is fundamentally bottlenecked by pathologically flat saddle points in extreme high-dimensional landscapes. Motivated by this challenge, we analyze the saddle-point escape dynamics of the emerging Muon optimizer, demonstrating its resilience against the O(D)\mathcal{O}(D) dimensional curse that severely traps element-wise adaptive optimizers like AdamW. By extending generalized matrix perturbation theory, we develop a theoretical framework to capture Muon's non-equilibrium optimization trajectories. This theoretical machinery mathematically proves that Muon elegantly bypasses the dimensional curse via a non-linear spectral shaping mechanism. By leveraging resolvent functional calculus and macroscopic Cauchy contour integration, we avoid isotropic noise assumptions and Tracy-Widom edge singularities. We establish that structural incoherence securely shields the trajectory from orthogonal drift, enabling a dimension-free saddle-point escape, and triggering a deterministic O(1)\mathcal{O}(1) discrete ballistic ejection under sufficient spectral gap. Consequently, we provide an algebraically dimension-free escape bound for Muon, formalizing the underlying mechanics of its non-convex optimization dynamics.

Cite

@article{arxiv.2605.09331,
  title  = {Dimension-Free Saddle-Point Escape in Muon},
  author = {Yanlin Long and Yufei Gu and Zeke Xie},
  journal= {arXiv preprint arXiv:2605.09331},
  year   = {2026}
}

Comments

33 pages, 5 figures. Preprint

R2 v1 2026-07-01T13:01:15.772Z