{"title":"Homeomorphism types of the Bowditch boundaries of infinite-ended relatively hyperbolic groups","authors":"Ravi Tomar","doi":"10.1515/jgth-2023-0264","DOIUrl":null,"url":null,"abstract":"For <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mi>n</m:mi> <m:mo>≥</m:mo> <m:mn>2</m:mn> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2023-0264_ineq_0001.png\"/> <jats:tex-math>n\\geq 2</jats:tex-math> </jats:alternatives> </jats:inline-formula>, let <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:msub> <m:mi>G</m:mi> <m:mn>1</m:mn> </m:msub> <m:mo>=</m:mo> <m:mrow> <m:msub> <m:mi>A</m:mi> <m:mn>1</m:mn> </m:msub> <m:mo lspace=\"0.222em\" rspace=\"0.222em\">∗</m:mo> <m:mi mathvariant=\"normal\">⋯</m:mi> <m:mo lspace=\"0.222em\" rspace=\"0.222em\">∗</m:mo> <m:msub> <m:mi>A</m:mi> <m:mi>n</m:mi> </m:msub> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2023-0264_ineq_0002.png\"/> <jats:tex-math>G_{1}=A_{1}\\ast\\dots\\ast A_{n}</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:msub> <m:mi>G</m:mi> <m:mn>2</m:mn> </m:msub> <m:mo>=</m:mo> <m:mrow> <m:msub> <m:mi>B</m:mi> <m:mn>1</m:mn> </m:msub> <m:mo lspace=\"0.222em\" rspace=\"0.222em\">∗</m:mo> <m:mi mathvariant=\"normal\">⋯</m:mi> <m:mo lspace=\"0.222em\" rspace=\"0.222em\">∗</m:mo> <m:msub> <m:mi>B</m:mi> <m:mi>n</m:mi> </m:msub> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2023-0264_ineq_0003.png\"/> <jats:tex-math>G_{2}=B_{1}\\ast\\dots\\ast B_{n}</jats:tex-math> </jats:alternatives> </jats:inline-formula> where the <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:msub> <m:mi>A</m:mi> <m:mi>i</m:mi> </m:msub> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2023-0264_ineq_0004.png\"/> <jats:tex-math>A_{i}</jats:tex-math> </jats:alternatives> </jats:inline-formula>’s and <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:msub> <m:mi>B</m:mi> <m:mi>i</m:mi> </m:msub> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2023-0264_ineq_0005.png\"/> <jats:tex-math>B_{i}</jats:tex-math> </jats:alternatives> </jats:inline-formula>’s are non-elementary relatively hyperbolic groups. Suppose that, for <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>i</m:mi> <m:mo>≤</m:mo> <m:mi>n</m:mi> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2023-0264_ineq_0006.png\"/> <jats:tex-math>1\\leq i\\leq n</jats:tex-math> </jats:alternatives> </jats:inline-formula>, the Bowditch boundary of <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:msub> <m:mi>A</m:mi> <m:mi>i</m:mi> </m:msub> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2023-0264_ineq_0004.png\"/> <jats:tex-math>A_{i}</jats:tex-math> </jats:alternatives> </jats:inline-formula> is homeomorphic to the Bowditch boundary of <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:msub> <m:mi>B</m:mi> <m:mi>i</m:mi> </m:msub> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2023-0264_ineq_0005.png\"/> <jats:tex-math>B_{i}</jats:tex-math> </jats:alternatives> </jats:inline-formula>. We show that the Bowditch boundary of <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:msub> <m:mi>G</m:mi> <m:mn>1</m:mn> </m:msub> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2023-0264_ineq_0009.png\"/> <jats:tex-math>G_{1}</jats:tex-math> </jats:alternatives> </jats:inline-formula> is homeomorphic to the Bowditch boundary of <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:msub> <m:mi>G</m:mi> <m:mn>2</m:mn> </m:msub> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_jgth-2023-0264_ineq_0010.png\"/> <jats:tex-math>G_{2}</jats:tex-math> </jats:alternatives> </jats:inline-formula>. We generalize this result to graphs of relatively hyperbolic groups with finite edge groups. This extends Martin–Świątkowski’s work in the context of relatively hyperbolic groups.","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","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-2023-0264","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
For n≥2n\geq 2, let G1=A1∗⋯∗AnG_{1}=A_{1}\ast\dots\ast A_{n} and G2=B1∗⋯∗BnG_{2}=B_{1}\ast\dots\ast B_{n} where the AiA_{i}’s and BiB_{i}’s are non-elementary relatively hyperbolic groups. Suppose that, for 1≤i≤n1\leq i\leq n, the Bowditch boundary of AiA_{i} is homeomorphic to the Bowditch boundary of BiB_{i}. We show that the Bowditch boundary of G1G_{1} is homeomorphic to the Bowditch boundary of G2G_{2}. We generalize this result to graphs of relatively hyperbolic groups with finite edge groups. This extends Martin–Świątkowski’s work in the context of relatively hyperbolic groups.
对于 n ≥ 2 n\geq 2 、让 G 1 = A 1 ∗ ⋯ ∗ A n G_{1}=A_{1}\astdots\ast A_{n} 和 G 2 = B 1 ∗ ⋯ ∗ B n G_{2}=B_{1}\astdots\ast B_{n} 其中 A i A_{i} 's 和 B i B_{i} 's 是非元素相对双曲群。假设对于 1 ≤ i ≤ n 1\leq i\leq n ,A i A_{i} 的鲍迪奇边界与 B i B_{i} 的鲍迪奇边界同构。我们证明 G 1 G_{1} 的鲍迪奇边界与 G 2 G_{2} 的鲍迪奇边界同构。我们将这一结果推广到具有有限边群的相对双曲群图。这扩展了马丁-西里ą托克斯基在相对双曲群背景下的工作。