2025/06/25 by Yiwen Chen, Chen, Yiwen, Warren Hare +3
Computer Science · Mathematics · #65K05 #90C06 #90C56 #Advanced Optimization Algorithms Research #FOS: Mathematics #Machine Learning and Algorithms #Optimization and Control (math.OC) #Stochastic Gradient Optimization Techniques
paper · pdf · doi:10.48550/arxiv.2506.20335
openalex publication_date 2025/06/25 · openalex created_date 2025/10/09 · openalex updated_date 2026/07/28
This paper proposes a random subspace trust-region algorithm for general convex-constrained derivative-free optimization (DFO) problems. Similar to previous random subspace DFO methods, the convergence of our algorithm requires a certain accuracy of models and a certain quality of subspaces. For model accuracy, we define a new class of models that is only required to provide reasonable accuracy on the projection of the constraint set onto the subspace. We provide a new geometry measure to make these models easy to analyze, construct, and manage. For subspace quality, we use the concentration of measure on the Grassmann manifold to provide a method to sample subspaces that preserve the first-order criticality measure by a certain fraction with a certain probability lower bound. Based on all these new theoretical results, we present an almost-sure global convergence and a worst-case complexity analysis of our algorithm. Numerical experiments on problems with dimensions up to 10000 demonstrate the reliable performance of our algorithm in high dimensions.