{ "id": "2409.06115", "version": "v1", "published": "2024-09-09T23:43:31.000Z", "updated": "2024-09-09T23:43:31.000Z", "title": "On the structure of extremal point-line arrangements", "authors": [ "Gabriel Currier", "Jozsef Solymosi", "Hung-Hsun Hans Yu" ], "comment": "8 pages, comments welcome!", "categories": [ "math.CO" ], "abstract": "In this note, we show that extremal Szemer\\'{e}di-Trotter configurations are rigid in the following sense: If $P,L$ are sets of points and lines determining at least $C|P|^{2/3}|L|^{2/3}$ incidences, then there exists a collection $P'$ of points of size at most $k = k_0(C)$ such that, heuristically, fixing those points fixes a positive fraction of the arrangement. That is, the incidence structure and a small number of points determine a large part of the arrangement. The key tools we use are the Guth-Katz polynomial partitioning, and also a result of Dvir, Garg, Oliveira and Solymosi that was used to show the rigidity of near-Sylvester-Gallai configurations.", "revisions": [ { "version": "v1", "updated": "2024-09-09T23:43:31.000Z" } ], "analyses": { "subjects": [ "52C30" ], "keywords": [ "extremal point-line arrangements", "large part", "points determine", "small number", "near-sylvester-gallai configurations" ], "note": { "typesetting": "TeX", "pages": 8, "language": "en", "license": "arXiv", "status": "editable" } } }