{ "id": "2207.09659", "version": "v1", "published": "2022-07-20T05:29:39.000Z", "updated": "2022-07-20T05:29:39.000Z", "title": "Decomposition of triangle-free planar graphs", "authors": [ "Rongxing Xu", "Xuding Zhu" ], "categories": [ "math.CO" ], "abstract": "A decomposition of a graph $G$ is a family of subgraphs of $G$ whose edge sets form a partition of $E(G)$. In this paper, we prove that every triangle-free planar graph $G$ can be decomposed into a $2$-degenerate graph and a matching. Consequently, every triangle-free planar graph $G$ has a matching $M$ such that $G-M$ is online 3-DP-colorable. This strengthens an earlier result in [R. \\v{S}krekovski, {\\em A Gr\\\"{o}tzsch-Type Theorem for List Colourings with Impropriety One}, Combin. Prob. Comput. 8 (1999), 493-507] that every triangle-free planar graph is $1$-defective $3$-choosable.", "revisions": [ { "version": "v1", "updated": "2022-07-20T05:29:39.000Z" } ], "analyses": { "keywords": [ "triangle-free planar graph", "decomposition", "edge sets form", "degenerate graph", "earlier result" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }