{ "id": "2207.06304", "version": "v1", "published": "2022-07-13T15:57:52.000Z", "updated": "2022-07-13T15:57:52.000Z", "title": "On the Iteration Complexity of Smoothed Proximal ALM for Nonconvex Optimization Problem with Convex Constraints", "authors": [ "Jiawei Zhang", "Wenqiang Pu", "Zhi-Quan Luo" ], "categories": [ "math.OC" ], "abstract": "It is well-known that the lower bound of iteration complexity for solving nonconvex unconstrained optimization problems is $\\Omega(1/\\epsilon^2)$, which can be achieved by standard gradient descent algorithm when the objective function is smooth. This lower bound still holds for nonconvex constrained problems, while it is still unknown whether a first-order method can achieve this lower bound. In this paper, we show that a simple single-loop first-order algorithm called smoothed proximal augmented Lagrangian method (ALM) can achieve such iteration complexity lower bound. The key technical contribution is a strong local error bound for a general convex constrained problem, which is of independent interest.", "revisions": [ { "version": "v1", "updated": "2022-07-13T15:57:52.000Z" } ], "analyses": { "keywords": [ "iteration complexity", "nonconvex optimization problem", "smoothed proximal alm", "convex constraints", "lower bound" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }