{ "id": "2404.01504", "version": "v1", "published": "2024-04-01T22:10:15.000Z", "updated": "2024-04-01T22:10:15.000Z", "title": "On the orthogonal Grünbaum partition problem in dimension three", "authors": [ "Gerardo L. Maldonado", "Edgardo Roldán-Pensado" ], "categories": [ "math.CO", "cs.CG" ], "abstract": "Gr\\\"unbaum's equipartition problem asked if for any measure on $\\mathbb{R}^d$ there are always $d$ hyperplanes which divide $\\mathbb{R}^d$ into $2^d$ $\\mu$-equal parts. This problem is known to have a positive answer for $d\\le 3$ and a negative one for $d\\ge 5$. A variant of this question is to require the hyperplanes to be mutually orthogonal. This variant is known to have a positive answer for $d\\le 2$ and there is reason to expect it to have a negative answer for $d\\ge 3$. In this note we exhibit measures that prove this. Additionally, we describe an algorithm that checks if a set of $8n$ in $\\mathbb{R}^3$ can be split evenly by $3$ mutually orthogonal planes. To our surprise, it seems the probability that a random set of $8$ points chosen uniformly and independently in the unit cube does not admit such a partition is less than $0.001$.", "revisions": [ { "version": "v1", "updated": "2024-04-01T22:10:15.000Z" } ], "analyses": { "keywords": [ "orthogonal grünbaum partition problem", "positive answer", "hyperplanes", "unit cube", "equal parts" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }