{ "id": "2401.06809", "version": "v1", "published": "2024-01-10T23:21:44.000Z", "updated": "2024-01-10T23:21:44.000Z", "title": "Greedy Newton: Newton's Method with Exact Line Search", "authors": [ "Betty Shea", "Mark Schmidt" ], "categories": [ "math.OC" ], "abstract": "A defining characteristic of Newton's method is local superlinear convergence within a neighbourhood of a strict local minimum. However, outside this neighborhood Newton's method can converge slowly or even diverge. A common approach to dealing with non-convergence is using a step size that is set by an Armijo backtracking line search. With suitable initialization the line-search preserves local superlinear convergence, but may give sub-optimal progress when not near a solution. In this work we consider Newton's method under an exact line search, which we call \"greedy Newton\" (GN). We show that this leads to an improved global convergence rate, while retaining a local superlinear convergence rate. We empirically show that GN may work better than backtracking Newton by allowing significantly larger step sizes.", "revisions": [ { "version": "v1", "updated": "2024-01-10T23:21:44.000Z" } ], "analyses": { "keywords": [ "exact line search", "newtons method", "greedy newton", "line-search preserves local superlinear convergence", "local superlinear convergence rate" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }