{"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":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1515/jgth-2024-0016","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","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 。