2025/07/23 by Goncalves, Max L. N., Grapiglia, Geovani N.
#FOS: Mathematics #Optimization and Control (math.OC)
paper · doi:10.48550/arxiv.2507.17556
In this paper, we develop and analyze sub-sampled trust-region methods for solving finite-sum optimization problems. These methods employ subsampling strategies to approximate the gradient and Hessian of the objective function, significantly reducing the overall computational cost. We propose a novel adaptive procedure for deterministically adjusting the sample size used for gradient (or gradient and Hessian) approximations. Furthermore, we establish worst-case iteration complexity bounds for obtaining approximate stationary points. More specifically, for a given εg, εH∈ (0,1), it is shown that an εg-approximate first-order stationary point is reached in at most O(εg-2 ) iterations, whereas an (εg,εH)-approximate second-order stationary point is reached in at most O(max\εg-2εH-1,εH-3\) iterations. Finally, numerical experiments illustrate the effectiveness of our new subsampling technique.