activity
20242026
collaborators

5 papers

math.NA2026

Hierarchical Muon: Tiled Newton-Schulz Updates for Efficient Muon Optimization

Ziyuan Tang, Tianshi Xu, Yousef Saad +1

Muon-type optimizers construct update directions for dense neural-network weights by applying a finite Newton-Schulz map to momentum-gradient matrices. For an matrix,…

math.NA2026

Design Criteria for SGD Preconditioners: Local Conditioning, Noise Floors, and Basin Stability

Mitchell Scott, Tianshi Xu, Ziyuan Tang +4

Stochastic Gradient Descent (SGD) often slows in the late stage of training due to anisotropic curvature and gradient noise. We analyze preconditioned SGD in the geometry induced b…

math.NA2026

Preconditioned Truncated Single-Sample Estimators for Scalable Stochastic Optimization

Tianshi Xu, Difeng Cai, Hua Huang +2

Many large-scale stochastic optimization algorithms involve repeated solutions of linear systems or evaluations of log-determinants. In these regimes, computing exact solutions is…

math.NA2025

Mixed Precision Orthogonalization-Free Projection Methods for Eigenvalue and Singular Value Problems

Tianshi Xu, Zechen Zhang, Jie Chen +2

Mixed-precision arithmetic offers significant computational advantages for large-scale matrix computation tasks, yet preserving accuracy and stability in eigenvalue problems and th…

math.NA2024

Anderson Acceleration with Truncated Gram-Schmidt

Ziyuan Tang, Tianshi Xu, Huan He +2

Anderson Acceleration (AA) is a popular algorithm designed to enhance the convergence of fixed-point iterations. In this paper, we introduce a variant of AA based on a Truncated Gr…