{"title":"Finite groups with a small proportion of vanishing elements","authors":"Dongfang Yang, Yu Zeng, Silvio Dolfi","doi":"10.1515/jgth-2024-0016","DOIUrl":null,"url":null,"abstract":"Let 𝐺 be a finite group and let <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:msub> <m:mi mathvariant=\"normal\">P</m:mi> <m:mi mathvariant=\"bold\">v</m:mi> </m:msub> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>G</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2024-0016_ineq_0001.png\"/> <jats:tex-math>\\mathrm{P}_{\\mathbf{v}}(G)</jats:tex-math> </jats:alternatives> </jats:inline-formula> be the proportion of elements <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mi>g</m:mi> <m:mo>∈</m:mo> <m:mi>G</m:mi> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2024-0016_ineq_0002.png\"/> <jats:tex-math>g\\in G</jats:tex-math> </jats:alternatives> </jats:inline-formula> such that <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mrow> <m:mi>χ</m:mi> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>g</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> <m:mo>=</m:mo> <m:mn>0</m:mn> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2024-0016_ineq_0003.png\"/> <jats:tex-math>\\chi(g)=0</jats:tex-math> </jats:alternatives> </jats:inline-formula> for some irreducible character 𝜒. In a recent paper, we proved that if <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mrow> <m:msub> <m:mi mathvariant=\"normal\">P</m:mi> <m:mi mathvariant=\"bold\">v</m:mi> </m:msub> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>G</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> <m:mo><</m:mo> <m:mrow> <m:msub> <m:mi mathvariant=\"normal\">P</m:mi> <m:mi mathvariant=\"bold\">v</m:mi> </m:msub> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:msub> <m:mi>A</m:mi> <m:mn>7</m:mn> </m:msub> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2024-0016_ineq_0004.png\"/> <jats:tex-math>\\mathrm{P}_{\\mathbf{v}}(G)<\\mathrm{P}_{\\mathbf{v}}(A_{7})</jats:tex-math> </jats:alternatives> </jats:inline-formula>, then <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mrow> <m:msub> <m:mi mathvariant=\"normal\">P</m:mi> <m:mi mathvariant=\"bold\">v</m:mi> </m:msub> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>G</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> <m:mo>=</m:mo> <m:mrow> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mrow> <m:mi>m</m:mi> <m:mo>−</m:mo> <m:mn>1</m:mn> </m:mrow> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> <m:mo>/</m:mo> <m:mi>m</m:mi> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2024-0016_ineq_0005.png\"/> <jats:tex-math>\\mathrm{P}_{\\mathbf{v}}(G)=(m-1)/m</jats:tex-math> </jats:alternatives> </jats:inline-formula> for some <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mn>1</m:mn> <m:mo>≤</m:mo> <m:mi>m</m:mi> <m:mo>≤</m:mo> <m:mn>6</m:mn> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2024-0016_ineq_0006.png\"/> <jats:tex-math>1\\leq m\\leq 6</jats:tex-math> </jats:alternatives> </jats:inline-formula>. Here we classify all the finite groups 𝐺 such that <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mrow> <m:msub> <m:mi mathvariant=\"normal\">P</m:mi> <m:mi mathvariant=\"bold\">v</m:mi> </m:msub> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>G</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> <m:mo>=</m:mo> <m:mrow> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mrow> <m:mi>m</m:mi> <m:mo>−</m:mo> <m:mn>1</m:mn> </m:mrow> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> <m:mo>/</m:mo> <m:mi>m</m:mi> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2024-0016_ineq_0005.png\"/> <jats:tex-math>\\mathrm{P}_{\\mathbf{v}}(G)=(m-1)/m</jats:tex-math> </jats:alternatives> </jats:inline-formula> and <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mi>m</m:mi> <m:mo>=</m:mo> <m:mrow> <m:mn>1</m:mn> <m:mo>,</m:mo> <m:mn>2</m:mn> <m:mo>,</m:mo> <m:mi mathvariant=\"normal\">…</m:mi> <m:mo>,</m:mo> <m:mn>6</m:mn> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2024-0016_ineq_0008.png\"/> <jats:tex-math>m=1,2,\\ldots,6</jats:tex-math> </jats:alternatives> </jats:inline-formula>.","PeriodicalId":50188,"journal":{"name":"Journal of Group Theory","volume":"62 1","pages":""},"PeriodicalIF":0.4000,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Group Theory","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1515/jgth-2024-0016","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Let 𝐺 be a finite group and let Pv(G)\mathrm{P}_{\mathbf{v}}(G) be the proportion of elements g∈Gg\in G such that χ(g)=0\chi(g)=0 for some irreducible character 𝜒. In a recent paper, we proved that if Pv(G)<Pv(A7)\mathrm{P}_{\mathbf{v}}(G)<\mathrm{P}_{\mathbf{v}}(A_{7}), then Pv(G)=(m−1)/m\mathrm{P}_{\mathbf{v}}(G)=(m-1)/m for some 1≤m≤61\leq m\leq 6. Here we classify all the finite groups 𝐺 such that Pv(G)=(m−1)/m\mathrm{P}_{\mathbf{v}}(G)=(m-1)/m and m=1,2,…,6m=1,2,\ldots,6.
让𝐺 是一个有限群,并让 P v ( G ) \mathrm{P}_{\mathbf{v}}(G) 是元素 g ∈ G g\in G 中的比例,使得对于某个不可还原字符𝜒,χ ( g ) = 0 \chi(g)=0 。在最近的一篇论文中,我们证明了如果 P v ( G ) < P v ( A 7 ) \mathrm{P}_{\mathbf{v}}(G)<;\mathrm{P}_{\mathbf{v}}(A_{7}) , then P v ( G ) = ( m - 1 ) / m \mathrm{P}_{\mathbf{v}}(G)=(m-1)/m for some 1 ≤ m ≤ 6 1\leq m\leq 6 .这里我们将所有有限群𝐺进行分类,使得 P v ( G ) = ( m - 1 ) / m \mathrm{P}_{\mathbf{v}}(G)=(m-1)/m 且 m = 1 , 2 , ... , 6 m=1,2,\ldots,6 。
期刊介绍:
The Journal of Group Theory is devoted to the publication of original research articles in all aspects of group theory. Articles concerning applications of group theory and articles from research areas which have a significant impact on group theory will also be considered.
Topics:
Group Theory-
Representation Theory of Groups-
Computational Aspects of Group Theory-
Combinatorics and Graph Theory-
Algebra and Number Theory