{ "id": "2305.18252", "version": "v1", "published": "2023-05-29T17:20:13.000Z", "updated": "2023-05-29T17:20:13.000Z", "title": "On MaxCut and the Lovász theta function", "authors": [ "Igor Balla", "Oliver Janzer", "Benny Sudakov" ], "comment": "7 pages", "categories": [ "math.CO" ], "abstract": "In this short note we prove a lower bound for the MaxCut of a graph in terms of the Lov\\'asz theta function of its complement. We combine this with known bounds on the Lov\\'asz theta function of complements of $H$-free graphs to recover many known results on the MaxCut of $H$-free graphs. In particular, we give a new, very short proof of a conjecture of Alon, Krivelevich and Sudakov about the MaxCut of graphs with no cycles of length $r$.", "revisions": [ { "version": "v1", "updated": "2023-05-29T17:20:13.000Z" } ], "analyses": { "keywords": [ "lovász theta function", "lovasz theta function", "free graphs", "lower bound", "short note" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable" } } }