Polyak Step Size
The Polyak step size is an adaptive learning rate method for optimization algorithms like stochastic gradient descent (SGD), aiming to automatically adjust the step size during training, eliminating the need for manual tuning. Current research focuses on extending its application to reinforcement learning and improving its robustness and convergence properties, particularly in non-convex settings and for over-parameterized models, often incorporating techniques like preconditioning and variance reduction. This research is significant because efficient and robust optimization is crucial for many machine learning applications, and the Polyak step size offers a promising approach to improve the performance and stability of various algorithms.