{"title":"Subsquares in Random Latin Rectangles","authors":"Jack Allsop, Ian M. Wanless","doi":"10.1007/s00493-025-00156-0","DOIUrl":null,"url":null,"abstract":"<p>Suppose that <i>k</i> is a function of <i>n</i> and . We show that with probability <span>\\(1-O(1/n)\\)</span>, a uniformly random <span>\\(k\\times n\\)</span> Latin rectangle contains no proper Latin subsquare of order 4 or more, proving a conjecture of Divoux, Kelly, Kennedy and Sidhu. We also show that the expected number of subsquares of order 3 is bounded and find that the expected number of subsquares of order 2 is <span>\\(\\left( {\\begin{array}{c}k\\\\ 2\\end{array}}\\right) (1/2+o(1))\\)</span> for all <span>\\(k\\leqslant n\\)</span>.</p>","PeriodicalId":50666,"journal":{"name":"Combinatorica","volume":"462 1","pages":""},"PeriodicalIF":1.0000,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Combinatorica","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s00493-025-00156-0","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Suppose that k is a function of n and . We show that with probability \(1-O(1/n)\), a uniformly random \(k\times n\) Latin rectangle contains no proper Latin subsquare of order 4 or more, proving a conjecture of Divoux, Kelly, Kennedy and Sidhu. We also show that the expected number of subsquares of order 3 is bounded and find that the expected number of subsquares of order 2 is \(\left( {\begin{array}{c}k\\ 2\end{array}}\right) (1/2+o(1))\) for all \(k\leqslant n\).
期刊介绍:
COMBINATORICA publishes research papers in English in a variety of areas of combinatorics and the theory of computing, with particular emphasis on general techniques and unifying principles. Typical but not exclusive topics covered by COMBINATORICA are
- Combinatorial structures (graphs, hypergraphs, matroids, designs, permutation groups).
- Combinatorial optimization.
- Combinatorial aspects of geometry and number theory.
- Algorithms in combinatorics and related fields.
- Computational complexity theory.
- Randomization and explicit construction in combinatorics and algorithms.