{"title":"向量空间中的对偶关联和t-设计","authors":"Kristijan Tabak","doi":"10.1002/jcd.21922","DOIUrl":null,"url":null,"abstract":"<p>Let <math>\n <semantics>\n <mrow>\n <mi>V</mi>\n </mrow>\n <annotation> $V$</annotation>\n </semantics></math> be an <math>\n <semantics>\n <mrow>\n <mi>n</mi>\n </mrow>\n <annotation> $n$</annotation>\n </semantics></math>-dimensional vector space over <math>\n <semantics>\n <mrow>\n <msub>\n <mi>F</mi>\n \n <mi>q</mi>\n </msub>\n </mrow>\n <annotation> ${{\\mathbb{F}}}_{q}$</annotation>\n </semantics></math> and <math>\n <semantics>\n <mrow>\n <mi>H</mi>\n </mrow>\n <annotation> ${\\rm{ {\\mathcal H} }}$</annotation>\n </semantics></math> is any set of <math>\n <semantics>\n <mrow>\n <mi>k</mi>\n </mrow>\n <annotation> $k$</annotation>\n </semantics></math>-dimensional subspaces of <math>\n <semantics>\n <mrow>\n <mi>V</mi>\n </mrow>\n <annotation> $V$</annotation>\n </semantics></math>. We construct two incidence structures <math>\n <semantics>\n <mrow>\n <msub>\n <mi>D</mi>\n \n <mrow>\n <mi>m</mi>\n \n <mi>a</mi>\n \n <mi>x</mi>\n </mrow>\n </msub>\n \n <mrow>\n <mo>(</mo>\n \n <mi>H</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation> ${{\\mathscr{D}}}_{max}({\\rm{ {\\mathcal H} }})$</annotation>\n </semantics></math> and <math>\n <semantics>\n <mrow>\n <msub>\n <mi>D</mi>\n \n <mrow>\n <mi>m</mi>\n \n <mi>i</mi>\n \n <mi>n</mi>\n </mrow>\n </msub>\n \n <mrow>\n <mo>(</mo>\n \n <mi>H</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation> ${{\\mathscr{D}}}_{min}({\\rm{ {\\mathcal H} }})$</annotation>\n </semantics></math> using subspaces from <math>\n <semantics>\n <mrow>\n <mi>H</mi>\n </mrow>\n <annotation> ${\\rm{ {\\mathcal H} }}$</annotation>\n </semantics></math>. The points are subspaces from <math>\n <semantics>\n <mrow>\n <mi>H</mi>\n </mrow>\n <annotation> ${\\rm{ {\\mathcal H} }}$</annotation>\n </semantics></math>. The blocks of <math>\n <semantics>\n <mrow>\n <msub>\n <mi>D</mi>\n \n <mrow>\n <mi>m</mi>\n \n <mi>a</mi>\n \n <mi>x</mi>\n </mrow>\n </msub>\n \n <mrow>\n <mo>(</mo>\n \n <mi>H</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation> ${{\\mathscr{D}}}_{max}({\\rm{ {\\mathcal H} }})$</annotation>\n </semantics></math> are indexed by all hyperplanes of <math>\n <semantics>\n <mrow>\n <mi>V</mi>\n </mrow>\n <annotation> $V$</annotation>\n </semantics></math>, while the blocks of <math>\n <semantics>\n <mrow>\n <msub>\n <mi>D</mi>\n \n <mrow>\n <mi>m</mi>\n \n <mi>i</mi>\n \n <mi>n</mi>\n </mrow>\n </msub>\n \n <mrow>\n <mo>(</mo>\n \n <mi>H</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation> ${{\\mathscr{D}}}_{min}({\\rm{ {\\mathcal H} }})$</annotation>\n </semantics></math> are indexed by all subspaces of dimension 1. We show that <math>\n <semantics>\n <mrow>\n <msub>\n <mi>D</mi>\n \n <mrow>\n <mi>m</mi>\n \n <mi>a</mi>\n \n <mi>x</mi>\n </mrow>\n </msub>\n \n <mrow>\n <mo>(</mo>\n \n <mi>H</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation> ${{\\mathscr{D}}}_{max}({\\rm{ {\\mathcal H} }})$</annotation>\n </semantics></math> and <math>\n <semantics>\n <mrow>\n <msub>\n <mi>D</mi>\n \n <mrow>\n <mi>m</mi>\n \n <mi>i</mi>\n \n <mi>n</mi>\n </mrow>\n </msub>\n \n <mrow>\n <mo>(</mo>\n \n <mi>H</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation> ${{\\mathscr{D}}}_{min}({\\rm{ {\\mathcal H} }})$</annotation>\n </semantics></math> are dual in the sense that their incidence matrices are dependent, one can be calculated from the other. Additionally, if <math>\n <semantics>\n <mrow>\n <mi>H</mi>\n </mrow>\n <annotation> ${\\rm{ {\\mathcal H} }}$</annotation>\n </semantics></math> is a <math>\n <semantics>\n <mrow>\n <mi>t</mi>\n \n <mo>−</mo>\n \n <msub>\n <mrow>\n <mo>(</mo>\n \n <mrow>\n <mi>n</mi>\n \n <mo>,</mo>\n \n <mi>k</mi>\n \n <mo>,</mo>\n \n <mi>λ</mi>\n </mrow>\n \n <mo>)</mo>\n </mrow>\n \n <mi>q</mi>\n </msub>\n </mrow>\n <annotation> $t-{(n,k,\\lambda )}_{q}$</annotation>\n </semantics></math>-design we prove new matrix equations for incidence matrices of <math>\n <semantics>\n <mrow>\n <msub>\n <mi>D</mi>\n \n <mrow>\n <mi>m</mi>\n \n <mi>a</mi>\n \n <mi>x</mi>\n </mrow>\n </msub>\n \n <mrow>\n <mo>(</mo>\n \n <mi>H</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation> ${{\\mathscr{D}}}_{max}({\\rm{ {\\mathcal H} }})$</annotation>\n </semantics></math> and <math>\n <semantics>\n <mrow>\n <msub>\n <mi>D</mi>\n \n <mrow>\n <mi>m</mi>\n \n <mi>i</mi>\n \n <mi>n</mi>\n </mrow>\n </msub>\n \n <mrow>\n <mo>(</mo>\n \n <mi>H</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation> ${{\\mathscr{D}}}_{min}({\\rm{ {\\mathcal H} }})$</annotation>\n </semantics></math>.</p>","PeriodicalId":15389,"journal":{"name":"Journal of Combinatorial Designs","volume":"32 1","pages":"46-52"},"PeriodicalIF":0.5000,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Dual incidences and t-designs in vector spaces\",\"authors\":\"Kristijan Tabak\",\"doi\":\"10.1002/jcd.21922\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Let <math>\\n <semantics>\\n <mrow>\\n <mi>V</mi>\\n </mrow>\\n <annotation> $V$</annotation>\\n </semantics></math> be an <math>\\n <semantics>\\n <mrow>\\n <mi>n</mi>\\n </mrow>\\n <annotation> $n$</annotation>\\n </semantics></math>-dimensional vector space over <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>F</mi>\\n \\n <mi>q</mi>\\n </msub>\\n </mrow>\\n <annotation> ${{\\\\mathbb{F}}}_{q}$</annotation>\\n </semantics></math> and <math>\\n <semantics>\\n <mrow>\\n <mi>H</mi>\\n </mrow>\\n <annotation> ${\\\\rm{ {\\\\mathcal H} }}$</annotation>\\n </semantics></math> is any set of <math>\\n <semantics>\\n <mrow>\\n <mi>k</mi>\\n </mrow>\\n <annotation> $k$</annotation>\\n </semantics></math>-dimensional subspaces of <math>\\n <semantics>\\n <mrow>\\n <mi>V</mi>\\n </mrow>\\n <annotation> $V$</annotation>\\n </semantics></math>. We construct two incidence structures <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>D</mi>\\n \\n <mrow>\\n <mi>m</mi>\\n \\n <mi>a</mi>\\n \\n <mi>x</mi>\\n </mrow>\\n </msub>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>H</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation> ${{\\\\mathscr{D}}}_{max}({\\\\rm{ {\\\\mathcal H} }})$</annotation>\\n </semantics></math> and <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>D</mi>\\n \\n <mrow>\\n <mi>m</mi>\\n \\n <mi>i</mi>\\n \\n <mi>n</mi>\\n </mrow>\\n </msub>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>H</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation> ${{\\\\mathscr{D}}}_{min}({\\\\rm{ {\\\\mathcal H} }})$</annotation>\\n </semantics></math> using subspaces from <math>\\n <semantics>\\n <mrow>\\n <mi>H</mi>\\n </mrow>\\n <annotation> ${\\\\rm{ {\\\\mathcal H} }}$</annotation>\\n </semantics></math>. The points are subspaces from <math>\\n <semantics>\\n <mrow>\\n <mi>H</mi>\\n </mrow>\\n <annotation> ${\\\\rm{ {\\\\mathcal H} }}$</annotation>\\n </semantics></math>. The blocks of <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>D</mi>\\n \\n <mrow>\\n <mi>m</mi>\\n \\n <mi>a</mi>\\n \\n <mi>x</mi>\\n </mrow>\\n </msub>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>H</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation> ${{\\\\mathscr{D}}}_{max}({\\\\rm{ {\\\\mathcal H} }})$</annotation>\\n </semantics></math> are indexed by all hyperplanes of <math>\\n <semantics>\\n <mrow>\\n <mi>V</mi>\\n </mrow>\\n <annotation> $V$</annotation>\\n </semantics></math>, while the blocks of <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>D</mi>\\n \\n <mrow>\\n <mi>m</mi>\\n \\n <mi>i</mi>\\n \\n <mi>n</mi>\\n </mrow>\\n </msub>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>H</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation> ${{\\\\mathscr{D}}}_{min}({\\\\rm{ {\\\\mathcal H} }})$</annotation>\\n </semantics></math> are indexed by all subspaces of dimension 1. We show that <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>D</mi>\\n \\n <mrow>\\n <mi>m</mi>\\n \\n <mi>a</mi>\\n \\n <mi>x</mi>\\n </mrow>\\n </msub>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>H</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation> ${{\\\\mathscr{D}}}_{max}({\\\\rm{ {\\\\mathcal H} }})$</annotation>\\n </semantics></math> and <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>D</mi>\\n \\n <mrow>\\n <mi>m</mi>\\n \\n <mi>i</mi>\\n \\n <mi>n</mi>\\n </mrow>\\n </msub>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>H</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation> ${{\\\\mathscr{D}}}_{min}({\\\\rm{ {\\\\mathcal H} }})$</annotation>\\n </semantics></math> are dual in the sense that their incidence matrices are dependent, one can be calculated from the other. Additionally, if <math>\\n <semantics>\\n <mrow>\\n <mi>H</mi>\\n </mrow>\\n <annotation> ${\\\\rm{ {\\\\mathcal H} }}$</annotation>\\n </semantics></math> is a <math>\\n <semantics>\\n <mrow>\\n <mi>t</mi>\\n \\n <mo>−</mo>\\n \\n <msub>\\n <mrow>\\n <mo>(</mo>\\n \\n <mrow>\\n <mi>n</mi>\\n \\n <mo>,</mo>\\n \\n <mi>k</mi>\\n \\n <mo>,</mo>\\n \\n <mi>λ</mi>\\n </mrow>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mi>q</mi>\\n </msub>\\n </mrow>\\n <annotation> $t-{(n,k,\\\\lambda )}_{q}$</annotation>\\n </semantics></math>-design we prove new matrix equations for incidence matrices of <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>D</mi>\\n \\n <mrow>\\n <mi>m</mi>\\n \\n <mi>a</mi>\\n \\n <mi>x</mi>\\n </mrow>\\n </msub>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>H</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation> ${{\\\\mathscr{D}}}_{max}({\\\\rm{ {\\\\mathcal H} }})$</annotation>\\n </semantics></math> and <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>D</mi>\\n \\n <mrow>\\n <mi>m</mi>\\n \\n <mi>i</mi>\\n \\n <mi>n</mi>\\n </mrow>\\n </msub>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>H</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation> ${{\\\\mathscr{D}}}_{min}({\\\\rm{ {\\\\mathcal H} }})$</annotation>\\n </semantics></math>.</p>\",\"PeriodicalId\":15389,\"journal\":{\"name\":\"Journal of Combinatorial Designs\",\"volume\":\"32 1\",\"pages\":\"46-52\"},\"PeriodicalIF\":0.5000,\"publicationDate\":\"2023-10-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Combinatorial Designs\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/jcd.21922\",\"RegionNum\":4,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Combinatorial Designs","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/jcd.21922","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
摘要
设V$ V$是F $ q ${{\mathbb{F}}}_{q}$和H上的n$ n维向量空间${\rm{{\mathcal H}}}$是V$ V$的k$ k$维子空间的任意集合。我们构造了两个关联结构D m a x (H)${{\mathscr{D}}}_{max}({\rm{{\mathcal H}}})$和D m i n (H)${{\mathscr{D}}}_{min}({\rm{\mathcal H}}})$使用H ${\rm{{\mathcal H}}}} $的子空间。这些点是H ${\rm{{\mathcal H}}}$的子空间。dmma x (H)的块${{\mathscr{D}}}_{max}({\rm{{\mathcal H}}})$由V$ V$的所有超平面索引,而dm块i n (H)${{\mathscr{D}}}_{min}({\rm{{\mathcal H}}})$由维度为1的所有子空间索引。我们证明了dmma x (H)${{\mathscr{D}}}_{max}({\rm{{\mathcal H}}})$和D m i n (H)${{\mathscr{D}}}_{min}({\rm{{\mathcal H}}})$是对偶的,因为它们的关联矩阵是相关的,一个可以从另一个计算出来。 另外,如果H ${\rm{{\mathcal H}}}$是t−(n),k ,λ) q $t-{(n,k,\ λ)}_{q}$ -设计证明了D m关联矩阵的新矩阵方程ax (H)$ {{\mathscr{D}}}_{max}({\rm{\mathcal H}}})$和Dmin (H)$ {{\mathscr{D}}}_{min}({\rm{{\mathcal H}}})$。
Let be an -dimensional vector space over and is any set of -dimensional subspaces of . We construct two incidence structures and using subspaces from . The points are subspaces from . The blocks of are indexed by all hyperplanes of , while the blocks of are indexed by all subspaces of dimension 1. We show that and are dual in the sense that their incidence matrices are dependent, one can be calculated from the other. Additionally, if is a -design we prove new matrix equations for incidence matrices of and .
期刊介绍:
The Journal of Combinatorial Designs is an international journal devoted to the timely publication of the most influential papers in the area of combinatorial design theory. All topics in design theory, and in which design theory has important applications, are covered, including:
block designs, t-designs, pairwise balanced designs and group divisible designs
Latin squares, quasigroups, and related algebras
computational methods in design theory
construction methods
applications in computer science, experimental design theory, and coding theory
graph decompositions, factorizations, and design-theoretic techniques in graph theory and extremal combinatorics
finite geometry and its relation with design theory.
algebraic aspects of design theory.
Researchers and scientists can depend on the Journal of Combinatorial Designs for the most recent developments in this rapidly growing field, and to provide a forum for both theoretical research and applications. All papers appearing in the Journal of Combinatorial Designs are carefully peer refereed.