{ "id": "2304.14579", "version": "v1", "published": "2023-04-28T00:46:27.000Z", "updated": "2023-04-28T00:46:27.000Z", "title": "Full Characterization of Color Degree Sequences in Complete Graphs Without Tricolored Triangles", "authors": [ "Anton Trygub" ], "comment": "7 pages", "categories": [ "math.CO" ], "abstract": "For an edge-colored complete graph, we define the color degree of a node as the number of colors appearing on edges incident to it. In this paper, we consider colorings that don't contain tricolored triangles (also called rainbow triangles); these colorings are also called Gallai colorings. We give a complete characterization of all possible color degree sequences $d_1 \\le d_2 \\le \\dots \\le d_n$ that can arise on a Gallai coloring of $K_n$: it is necessary and sufficient that \\[ \\sum_{i = k}^n \\frac{1}{2^{d_i - d_{k-1}}} \\ge 1 \\] holds for all $1 \\le k \\le n$, where $d_0=0$ for convenience. As a corollary, this gives another proof of a 2018 result of Fujita, Li, and Zhang who showed that the minimum color degree in such a coloring is at most $\\log_2n$.", "revisions": [ { "version": "v1", "updated": "2023-04-28T00:46:27.000Z" } ], "analyses": { "keywords": [ "color degree sequences", "full characterization", "dont contain tricolored triangles", "minimum color degree", "complete characterization" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable" } } }