4 papers
Obtaining Lower Query Complexities through Lightweight Zeroth-Order Proximal Gradient Algorithms
Bin Gu, Xiyuan Wei, Hualin Zhang +2
Zeroth-order (ZO) optimization is one key technique for machine learning problems where gradient calculation is expensive or impossible. Several variance reduced ZO proximal algori…
Hard-Thresholding Meets Evolution Strategies in Reinforcement Learning
Chengqian Gao, William de Vazelhes, Hualin Zhang +2
Evolution Strategies (ES) have emerged as a competitive alternative for model-free reinforcement learning, showcasing exemplary performance in tasks like Mujoco and Atari. Notably,…
Zeroth-Order Negative Curvature Finding: Escaping Saddle Points without Gradients
Hualin Zhang, Huan Xiong, Bin Gu
We consider escaping saddle points of nonconvex problems where only the function evaluations can be accessed. Although a variety of works have been proposed, the majority of them r…
Zeroth-Order Hard-Thresholding: Gradient Error vs. Expansivity
William de Vazelhes, Hualin Zhang, Huimin Wu +2
constrained optimization is prevalent in machine learning, particularly for high-dimensional problems, because it is a fundamental approach to achieve sparse learning. Har…