{ "id": "2411.12124", "version": "v1", "published": "2024-11-18T23:30:27.000Z", "updated": "2024-11-18T23:30:27.000Z", "title": "A note on the mutual-visibility coloring of hypercubes", "authors": [ "Maria Axenovich", "Dingyuan Liu" ], "comment": "4 pages, comments are welcome", "categories": [ "math.CO" ], "abstract": "A subset $M$ of vertices in a graph $G$ is a mutual-visibility set if for any two vertices $u,v\\in{M}$ there exists a shortest $u$-$v$ path in $G$ that contains no elements of $M$ as internal vertices. Let $\\chi_{\\mu}(G)$ be the least number of colors needed to color the vertices of $G$, so that each color class is a mutual-visibility set. Let $n\\in\\mathbb{N}$ and $Q_{n}$ be an $n$-dimensional hypercube. It has been shown that the maximum size of a mutual-visibility set in $Q_{n}$ is at least $\\Omega(2^{n})$. Klav\\v{z}ar, Kuziak, Valenzuela-Tripodoro, and Yero further asked whether it is true that $\\chi_{\\mu}(Q_{n})=O(1)$. In this note we answer their question in the negative by showing that $$\\omega(1)=\\chi_{\\mu}(Q_{n})=O(\\log\\log{n}).$$", "revisions": [ { "version": "v1", "updated": "2024-11-18T23:30:27.000Z" } ], "analyses": { "keywords": [ "mutual-visibility set", "mutual-visibility coloring", "color class", "dimensional hypercube", "internal vertices" ], "note": { "typesetting": "TeX", "pages": 4, "language": "en", "license": "arXiv", "status": "editable" } } }