• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

On the rigidity of finitely generated groups of homomorphisms of the circle

Research Project

Project/Area Number 19K23406
Research Category

Grant-in-Aid for Research Activity Start-up

Allocation TypeMulti-year Fund
Review Section 0201:Algebra, geometry, analysis, applied mathematics,and related fields
Research InstitutionUniversity of the Ryukyus (2022)
Ehime University (2019-2021)

Principal Investigator

Kato Motoko  琉球大学, 教育学部, 准教授 (00847593)

Project Period (FY) 2019-08-30 – 2023-03-31
Project Status Completed (Fiscal Year 2022)
Budget Amount *help
¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Fiscal Year 2020: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Keywords固定点性質 / CAT(0)空間への群作用 / 円の自己同相写像 / Richard Thompsonの群 / Thompson群 / CAT(0)空間 / 円の自己同相群 / 性質FH / 群作用の固定点性質
Outline of Research at the Start

本研究では, 幾何学的群論の手法を用い, 単位円の向きを保つ自己同相写像の成す群について, その有限生成無限部分群の構造を研究する. 特に, このような群のうち, Serreの性質FHと呼ばれる群作用の固定点性質を持つものの探索を目的とする.
円の自己同相写像の成す有限生成群のうち, Thompson群と呼ばれる有限表示無限単純群は, 広く研究されている. 本研究ではThompson群とその一般化が性質FHを弱めた性質を持つことに注目し, 円の自己同相写像の成す有限生成群の中でThompson群のある種の一般化として得られるものについて, 性質FH及びそれに関連する性質を研究する.

Outline of Final Research Achievements

On groups of homomorphisms of the circle, we studied fixed point properties of group actions on non-positively curved spaces. In this research, we showed relative fixed point properties for groups called ring groups, with respect to finitely generated subgroups of their commutator subgroups. As an application, we showed that Higman-Thompson groups T_n, which are generalizations of Richard Thompson's group T, admit fixed point properties for semi-simple actions on CAT(0) spaces of finite covering dimension. In the proof, we constructed new finite generating sets for every T_n and showed that every T_n has a structure of a ring group.

Academic Significance and Societal Importance of the Research Achievements

一般に固定点性質を持つ群の具体例を構成するのは難しいが, Richard Thompson群T, Vはそのような数少ない具体例の一つとして知られている. しかし, T_nが同様の固定点性質を持つかどうかは知られていなかった.本研究では, T_nがring群の構造を持つことを示した. この過程で, T_nの新たな有限生成系を構成した. この生成系は, T_nの自己相似性を反映するという意味で性質の良いものである. さらにそれを用いて, Tに対する証明の一般化の仮定における技術的な困難を回避することに成功した.

Report

(5 results)
  • 2022 Annual Research Report   Final Research Report ( PDF )
  • 2021 Research-status Report
  • 2020 Research-status Report
  • 2019 Research-status Report
  • Research Products

    (12 results)

All 2022 2021 2020 2019

All Journal Article (2 results) (of which Peer Reviewed: 2 results,  Open Access: 1 results) Presentation (10 results) (of which Int'l Joint Research: 2 results,  Invited: 9 results)

  • [Journal Article] Acylindrical hyperbolicity of Artin-Tits groups associated to triangle-free graphs and cones over square-free bipartite graphs2020

    • Author(s)
      Motoko Kato, Shin-ichi Oguni
    • Journal Title

      Glasgow Mathematical Journal

      Volume: Published Online Issue: 1 Pages: 1-14

    • DOI

      10.1017/s0017089520000555

    • Related Report
      2020 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] On groups whose actions on finite-dimensional CAT(0) spaces have global fixed points2019

    • Author(s)
      Kato Motoko
    • Journal Title

      Journal of Group Theory

      Volume: 22 Issue: 6 Pages: 1089-1099

    • DOI

      10.1515/jgth-2018-0116

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Presentation] リチャード・トンプソンの群とその応用2022

    • Author(s)
      加藤本子
    • Organizer
      暗号と及び情報セキュリティと数学の相関ワークショップ
    • Related Report
      2022 Annual Research Report
    • Invited
  • [Presentation] The Higman-Thompson groups and ring groups of homeomorphisms of the circle2022

    • Author(s)
      加藤本子
    • Organizer
      大阪大学トポロジーセミナー
    • Related Report
      2022 Annual Research Report
    • Invited
  • [Presentation] On acylindrical hyperbolicity of some Artin groups2021

    • Author(s)
      加藤本子
    • Organizer
      Quantum Math, Singularities and Applications
    • Related Report
      2020 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] On ring groups of homeomorphisms of the circle2021

    • Author(s)
      加藤本子
    • Organizer
      Thompson群とその周辺
    • Related Report
      2020 Research-status Report
    • Invited
  • [Presentation] On acylindrical hyperbolicity of some Artin groups2020

    • Author(s)
      加藤本子
    • Organizer
      2020年度日本数学会秋季総合分科会
    • Related Report
      2020 Research-status Report
  • [Presentation] On acylindrical hyperbolicity of some Artin groups2020

    • Author(s)
      加藤本子
    • Organizer
      Flat Structure and Singularities
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] ある種のArtin 群の非シリンダー的双曲性について2019

    • Author(s)
      加藤本子
    • Organizer
      松山TGSA セミナー
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Richard Thompson's groups and their actions on non-positively curved spaces2019

    • Author(s)
      加藤本子
    • Organizer
      岡潔女性数学者セミナー
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] 有限次元距離空間への群作用の固定点性質2019

    • Author(s)
      加藤本子
    • Organizer
      第66回トポロジーシンポジウム
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] 非正曲率距離空間への群作用の固定点性質2019

    • Author(s)
      加藤本子
    • Organizer
      名古屋大学幾何学セミナー
    • Related Report
      2019 Research-status Report
    • Invited

URL: 

Published: 2019-09-03   Modified: 2024-01-30  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi