{ "id": "1610.06514", "version": "v1", "published": "2016-10-20T17:39:22.000Z", "updated": "2016-10-20T17:39:22.000Z", "title": "Packing curves on surfaces with few intersections", "authors": [ "Tarik Aougab", "Ian Biringer", "Jonah Gaster" ], "categories": [ "math.GT" ], "abstract": "Przytycki has shown that the size $\\mathcal{N}_{k}(S)$ of a maximal collection of simple closed curves that pairwise intersect at most $k$ times on a topological surface $S$ grows at most as a polynomial in $|\\chi(S)|$ of degree $k^{2}+k+1$. In this paper, we narrow Przytycki's bounds by showing that $$ \\mathcal{N}_{k}(S) =O \\left( \\frac{ |\\chi|^{3k}}{ ( \\log |\\chi| )^2 } \\right) , $$ In particular, the size of a maximal 1-system grows sub-cubically in $|\\chi(S)|$. The proof uses a circle packing argument of Aougab-Souto and a bound for the number of curves of length at most $L$ on a hyperbolic surface. When the genus $g$ is fixed and the number of punctures $n$ grows, we can improve our estimates using a different argument to give $$ \\mathcal{N}_{k}(S) \\leq O(n^{2k+2}) . $$ Using similar techniques, we also obtain the sharp estimate $\\mathcal{N}_{2}(S)=\\Theta(n^3)$ when $k=2$ and $g$ is fixed.", "revisions": [ { "version": "v1", "updated": "2016-10-20T17:39:22.000Z" } ], "analyses": { "keywords": [ "packing curves", "intersections", "narrow przytyckis bounds", "sharp estimate", "similar techniques" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }