{"title":"论有限域上具有规定秩和部分迹的矩阵的万有引力","authors":"Kumar Balasubramanian , Krishna Kaipa , Himanshi Khurana","doi":"10.1016/j.laa.2024.10.011","DOIUrl":null,"url":null,"abstract":"<div><div>Let <em>F</em> be the finite field of order <em>q</em> and <span><math><mi>M</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>r</mi><mo>,</mo><mi>F</mi><mo>)</mo></math></span> be the set of <span><math><mi>n</mi><mo>×</mo><mi>n</mi></math></span> matrices of rank <em>r</em> over the field <em>F</em>. For <span><math><mi>α</mi><mo>∈</mo><mi>F</mi></math></span> and <span><math><mi>A</mi><mo>∈</mo><mi>M</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>F</mi><mo>)</mo></math></span>, let<span><span><span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mi>A</mi><mo>,</mo><mi>r</mi></mrow><mrow><mi>α</mi></mrow></msubsup><mo>=</mo><mrow><mo>{</mo><mi>X</mi><mo>∈</mo><mi>M</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>r</mi><mo>,</mo><mi>F</mi><mo>)</mo><mo>|</mo><mi>Tr</mi><mo>(</mo><mi>A</mi><mi>X</mi><mo>)</mo><mo>=</mo><mi>α</mi><mo>}</mo></mrow><mo>.</mo></math></span></span></span> In this article, we solve the problem of determining the cardinality of <span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mi>A</mi><mo>,</mo><mi>r</mi></mrow><mrow><mi>α</mi></mrow></msubsup></math></span>. We also solve the generalization of the problem to rectangular matrices.</div></div>","PeriodicalId":18043,"journal":{"name":"Linear Algebra and its Applications","volume":null,"pages":null},"PeriodicalIF":1.0000,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"On the cardinality of matrices with prescribed rank and partial trace over a finite field\",\"authors\":\"Kumar Balasubramanian , Krishna Kaipa , Himanshi Khurana\",\"doi\":\"10.1016/j.laa.2024.10.011\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Let <em>F</em> be the finite field of order <em>q</em> and <span><math><mi>M</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>r</mi><mo>,</mo><mi>F</mi><mo>)</mo></math></span> be the set of <span><math><mi>n</mi><mo>×</mo><mi>n</mi></math></span> matrices of rank <em>r</em> over the field <em>F</em>. For <span><math><mi>α</mi><mo>∈</mo><mi>F</mi></math></span> and <span><math><mi>A</mi><mo>∈</mo><mi>M</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>F</mi><mo>)</mo></math></span>, let<span><span><span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mi>A</mi><mo>,</mo><mi>r</mi></mrow><mrow><mi>α</mi></mrow></msubsup><mo>=</mo><mrow><mo>{</mo><mi>X</mi><mo>∈</mo><mi>M</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>r</mi><mo>,</mo><mi>F</mi><mo>)</mo><mo>|</mo><mi>Tr</mi><mo>(</mo><mi>A</mi><mi>X</mi><mo>)</mo><mo>=</mo><mi>α</mi><mo>}</mo></mrow><mo>.</mo></math></span></span></span> In this article, we solve the problem of determining the cardinality of <span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mi>A</mi><mo>,</mo><mi>r</mi></mrow><mrow><mi>α</mi></mrow></msubsup></math></span>. We also solve the generalization of the problem to rectangular matrices.</div></div>\",\"PeriodicalId\":18043,\"journal\":{\"name\":\"Linear Algebra and its Applications\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.0000,\"publicationDate\":\"2024-10-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Linear Algebra and its Applications\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0024379524003902\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Linear Algebra and its Applications","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0024379524003902","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
On the cardinality of matrices with prescribed rank and partial trace over a finite field
Let F be the finite field of order q and be the set of matrices of rank r over the field F. For and , let In this article, we solve the problem of determining the cardinality of . We also solve the generalization of the problem to rectangular matrices.
期刊介绍:
Linear Algebra and its Applications publishes articles that contribute new information or new insights to matrix theory and finite dimensional linear algebra in their algebraic, arithmetic, combinatorial, geometric, or numerical aspects. It also publishes articles that give significant applications of matrix theory or linear algebra to other branches of mathematics and to other sciences. Articles that provide new information or perspectives on the historical development of matrix theory and linear algebra are also welcome. Expository articles which can serve as an introduction to a subject for workers in related areas and which bring one to the frontiers of research are encouraged. Reviews of books are published occasionally as are conference reports that provide an historical record of major meetings on matrix theory and linear algebra.