{ "id": "2207.04254", "version": "v1", "published": "2022-07-09T11:45:27.000Z", "updated": "2022-07-09T11:45:27.000Z", "title": "The $\\!{}\\bmod k$ chromatic index of random graphs", "authors": [ "Fábio Botler", "Lucas Colucci", "Yoshiharu Kohayakawa" ], "comment": "12 pages, 1 figure", "categories": [ "math.CO" ], "abstract": "The $\\!{}\\bmod k$ chromatic index of a graph $G$ is the minimum number of colors needed to color the edges of $G$ in a way that the subgraph spanned by the edges of each color has all degrees congruent to $1\\!\\!\\pmod k$. Recently, the authors proved that the $\\!{}\\bmod k$ chromatic index of every graph is at most $198k-101$, improving, for large $k$, a result of Scott [Discrete Math. 175, 1-3 (1997), 289-291]. Here we study the $\\!{}\\bmod k$ chromatic index of random graphs. We prove that for every integer $k\\geq2$, there is $C_k>0$ such that if $p\\geq C_kn^{-1}\\log{n}$ and $n(1-p) \\rightarrow\\infty$ as $n\\to\\infty$, then the following holds: if $k$ is odd, then the $\\!{}\\bmod k$ chromatic index of $G(n,p)$ is asymptotically almost surely equal to $k$, while if $k$ is even, then the $\\!{}\\bmod k$ chromatic index of $G(2n,p)$ (respectively $G(2n+1,p)$) is asymptotically almost surely equal to $k$ (respectively $k+1$).", "revisions": [ { "version": "v1", "updated": "2022-07-09T11:45:27.000Z" } ], "analyses": { "subjects": [ "05C80", "05C15" ], "keywords": [ "chromatic index", "random graphs", "surely equal", "discrete math", "minimum number" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable" } } }