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New development of the coarse geometry of nonpositively curved spaces

Research Project

Project/Area Number 19K03471
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Review Section Basic Section 11020:Geometry-related
Research InstitutionTokyo Metropolitan University

Principal Investigator

Fukaya Tomohiro  東京都立大学, 理学研究科, 准教授 (40583456)

Project Period (FY) 2019-04-01 – 2024-03-31
Project Status Completed (Fiscal Year 2023)
Budget Amount *help
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2023: ¥260,000 (Direct Cost: ¥200,000、Indirect Cost: ¥60,000)
Fiscal Year 2022: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2021: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Keywords粗幾何学 / 粗凸空間 / 粗Baum-Connes予想 / 非正曲率空間 / 非可換幾何学 / 幾何学的群論 / Busemann空間 / 非正曲率 / coarsely convex space / coarse geometry / geometric group theory
Outline of Research at the Start

近年,リーマン多様体の範疇を超えた,負曲率および非正曲率を持つ距離空間の幾何学が提唱され,活発に研究されている.尾國新一氏との共同研究で導入した粗凸空間は,距離関数の凸性という意味での非正曲率を持ち,擬等長同型と空間の直積の二つの操作で閉じているという性質を持つ距離空間のクラスである.このクラスはグロモフ双曲空間とCAT(0)空間を含む.この距離空間の幾何学的な性質と,その境界の位相的な性質を解明することがこの研究の目的である.

Outline of Final Research Achievements

Gromov hyperbolic spaces are analogous to simply connected Riemannian manifolds of negative curvature, and there are many studies from the viewpoint of geometric group theory and noncommutative geometry. Recently, studies of "spaces of nonpositive curvatures" become very active. With Shin-ichi Oguni, we introduced "coarsely convex spaces", which include many spaces of nonpositive curvatures, like Gromov hyperbolic spaces, CAT(0) spaces, systolic complexes, and proper injective metric spaces. In 2017, We proved the coarse Baum-Connes conjecture for proper coarsely convex spaces with minimal knowledge of these spaces. In this project, we reconstructed the basic theory of coarsely convex spaces.

Academic Significance and Societal Importance of the Research Achievements

単連結完備負曲率リーマン多様体の粗幾何学における類似物が、Gromov双曲空間であり、これまで幾何学的群論や非可換幾何学の観点から数多の研究が為されて きた。近年、「負曲率」を「非正曲率」に置き換えた、様々な距離空間のクラスが活発に研究されている。尾國新一氏との共同研究で2017年に導入した粗凸空間、はそうした空間の多くを包含する非正曲率空間のクラスである。これまで、Gromov双曲空間、CAT(0)空間、systolic 複体、injective metric spacesなど、個別の設定で行われてきた「非正曲率距離空間」の研究を、粗凸空間という設定の元で、統一的な理論の構築を進められた。

Report

(6 results)
  • 2023 Annual Research Report   Final Research Report ( PDF )
  • 2022 Research-status Report
  • 2021 Research-status Report
  • 2020 Research-status Report
  • 2019 Research-status Report
  • Research Products

    (12 results)

All 2024 2023 2022 2021 2020 2019 Other

All Journal Article (4 results) (of which Peer Reviewed: 3 results,  Open Access: 1 results) Presentation (6 results) (of which Int'l Joint Research: 1 results,  Invited: 2 results) Book (1 results) Remarks (1 results)

  • [Journal Article] A topological product decomposition of Busemann space2024

    • Author(s)
      FUKAYA Tomohiro
    • Journal Title

      Journal of the Mathematical Society of Japan

      Volume: 76 Issue: 1 Pages: 269-281

    • DOI

      10.2969/jmsj/89738973

    • ISSN
      0025-5645, 1881-1167, 1881-2333
    • Related Report
      2023 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Visual maps between coarsely convex spaces2023

    • Author(s)
      Yuuhei Ezawa, Tomohiro Fukaya
    • Journal Title

      Kobe Journal of Mathematics

      Volume: 40 Pages: 7-45

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Visual maps between coarsely convex spaces2021

    • Author(s)
      Yuuhei Ezawa, Tomohiro Fukaya
    • Journal Title

      arXiv

      Volume: -

    • Related Report
      2020 Research-status Report
    • Open Access
  • [Journal Article] Coarse compactifications and controlled products2020

    • Author(s)
      Tomohiro Fukaya, Shin-ichi Oguni, Takamitsu Yamauchi
    • Journal Title

      Journal of Topology and Analysis

      Volume: online Issue: 04 Pages: 1-26

    • DOI

      10.1142/s1793525321500102

    • Related Report
      2022 Research-status Report
    • Peer Reviewed
  • [Presentation] Visual maps between coarsely convex spaces2023

    • Author(s)
      深谷友宏
    • Organizer
      微分幾何研究集会
    • Related Report
      2023 Annual Research Report
    • Invited
  • [Presentation] Busemann空間の位相的分解2022

    • Author(s)
      深谷友宏
    • Organizer
      日本数学会秋季総合分科会・幾何学分科会
    • Related Report
      2022 Research-status Report
  • [Presentation] Visual maps between coarsely convex spaces2022

    • Author(s)
      深谷友宏
    • Organizer
      集合論的および幾何学的トポロジーと関連分野への応用
    • Related Report
      2022 Research-status Report
  • [Presentation] Visual maps between coarsely convex spaces2021

    • Author(s)
      Tomohiro Fukaya
    • Organizer
      Geometric Group Theory in East Asia
    • Related Report
      2020 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] 粗凸空間に作用する群の例2019

    • Author(s)
      深谷友宏
    • Organizer
      日本数学会秋季総合分科会・幾何学分科会
    • Related Report
      2019 Research-status Report
  • [Presentation] 粗幾何学入門1,22019

    • Author(s)
      深谷友宏
    • Organizer
      阿蘇幾何学研究集会
    • Related Report
      2019 Research-status Report
  • [Book] 粗幾何学入門2019

    • Author(s)
      深谷友宏
    • Total Pages
      200
    • Publisher
      サイエンス社
    • ISBN
      9784781914596
    • Related Report
      2019 Research-status Report
  • [Remarks]

    • URL

      https://www.comp.tmu.ac.jp/tomohirofukaya/index.shtml

    • Related Report
      2022 Research-status Report

URL: 

Published: 2019-04-18   Modified: 2025-01-30  

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