{ "id": "1101.1488", "version": "v1", "published": "2011-01-07T18:06:26.000Z", "updated": "2011-01-07T18:06:26.000Z", "title": "Lines induced by bichromatic point sets", "authors": [ "Louis Theran" ], "categories": [ "math.CO" ], "abstract": "An important theorem of Beck says that any point set in the Euclidean plane is either ``nearly general position'' or ``nearly collinear'': there is a constant C>0 such that, given n points in the plane with at most r$ of them collinear, the number of lines induced by the points is at least Cr(n-r). Recent work of Gutkin-Rams on billiards orbits requires the following elaboration of Beck's Theorem to bichromatic point sets: there is a constant C>0 such that, given n red points and n blue points in the plane with at most r of them collinear, the number of lines spanning at least one point of each color is at least Cr(2n-r).", "revisions": [ { "version": "v1", "updated": "2011-01-07T18:06:26.000Z" } ], "analyses": { "keywords": [ "bichromatic point sets", "beck says", "becks theorem", "general position" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1101.1488T" } } }