{"title":"关于三维正交格伦鲍姆分割问题","authors":"Gerardo L. Maldonado, Edgardo Roldán-Pensado","doi":"10.1016/j.comgeo.2024.102149","DOIUrl":null,"url":null,"abstract":"<div><div>Grünbaum's equipartition problem asked if for any measure <em>μ</em> on <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi></mrow></msup></math></span> there are always <em>d</em> hyperplanes which divide <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi></mrow></msup></math></span> into <span><math><msup><mrow><mn>2</mn></mrow><mrow><mi>d</mi></mrow></msup></math></span> <em>μ</em>-equal parts. This problem is known to have a positive answer for <span><math><mi>d</mi><mo>≤</mo><mn>3</mn></math></span> and a negative one for <span><math><mi>d</mi><mo>≥</mo><mn>5</mn></math></span>. A variant of this question is to require the hyperplanes to be mutually orthogonal. This variant is known to have a positive answer for <span><math><mi>d</mi><mo>≤</mo><mn>2</mn></math></span> and there is reason to expect it to have a negative answer for <span><math><mi>d</mi><mo>≥</mo><mn>3</mn></math></span>. In this note we exhibit measures that prove this. Additionally, we describe an algorithm that checks if a set of 8<em>n</em> in <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span> 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.</div></div>","PeriodicalId":51001,"journal":{"name":"Computational Geometry-Theory and Applications","volume":null,"pages":null},"PeriodicalIF":0.4000,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"On the orthogonal Grünbaum partition problem in dimension three\",\"authors\":\"Gerardo L. Maldonado, Edgardo Roldán-Pensado\",\"doi\":\"10.1016/j.comgeo.2024.102149\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Grünbaum's equipartition problem asked if for any measure <em>μ</em> on <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi></mrow></msup></math></span> there are always <em>d</em> hyperplanes which divide <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi></mrow></msup></math></span> into <span><math><msup><mrow><mn>2</mn></mrow><mrow><mi>d</mi></mrow></msup></math></span> <em>μ</em>-equal parts. This problem is known to have a positive answer for <span><math><mi>d</mi><mo>≤</mo><mn>3</mn></math></span> and a negative one for <span><math><mi>d</mi><mo>≥</mo><mn>5</mn></math></span>. A variant of this question is to require the hyperplanes to be mutually orthogonal. This variant is known to have a positive answer for <span><math><mi>d</mi><mo>≤</mo><mn>2</mn></math></span> and there is reason to expect it to have a negative answer for <span><math><mi>d</mi><mo>≥</mo><mn>3</mn></math></span>. In this note we exhibit measures that prove this. Additionally, we describe an algorithm that checks if a set of 8<em>n</em> in <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span> 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.</div></div>\",\"PeriodicalId\":51001,\"journal\":{\"name\":\"Computational Geometry-Theory and Applications\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.4000,\"publicationDate\":\"2024-10-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Computational Geometry-Theory and Applications\",\"FirstCategoryId\":\"94\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0925772124000713\",\"RegionNum\":4,\"RegionCategory\":\"计算机科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computational Geometry-Theory and Applications","FirstCategoryId":"94","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0925772124000713","RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATHEMATICS","Score":null,"Total":0}
On the orthogonal Grünbaum partition problem in dimension three
Grünbaum's equipartition problem asked if for any measure μ on there are always d hyperplanes which divide into μ-equal parts. This problem is known to have a positive answer for and a negative one for . A variant of this question is to require the hyperplanes to be mutually orthogonal. This variant is known to have a positive answer for and there is reason to expect it to have a negative answer for . In this note we exhibit measures that prove this. Additionally, we describe an algorithm that checks if a set of 8n in 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.
期刊介绍:
Computational Geometry is a forum for research in theoretical and applied aspects of computational geometry. The journal publishes fundamental research in all areas of the subject, as well as disseminating information on the applications, techniques, and use of computational geometry. Computational Geometry publishes articles on the design and analysis of geometric algorithms. All aspects of computational geometry are covered, including the numerical, graph theoretical and combinatorial aspects. Also welcomed are computational geometry solutions to fundamental problems arising in computer graphics, pattern recognition, robotics, image processing, CAD-CAM, VLSI design and geographical information systems.
Computational Geometry features a special section containing open problems and concise reports on implementations of computational geometry tools.