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Smooth structures of 4-manifolds and knots

Research Project

Project/Area Number 19K03491
Research Category

Grant-in-Aid for Scientific Research (C)

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

Principal Investigator

Yasui Kouichi  大阪大学, 大学院情報科学研究科, 准教授 (70547009)

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 2021: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2020: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Keywords4次元トポロジー / 4次元多様体 / 微分構造 / 種数関数 / コルク / 単純型予想 / Seiberg-Witten 不変量 / Bauer-Furuta 不変量 / トポロジー / 4次元多様体 / 安定化 / 随伴不等式 / 結び目 / ハンドル体 / Stein 多様体
Outline of Research at the Start

多様体と呼ばれる空間の微分構造の分類は,位相幾何学における最も基本的な問題の1つである.しかし,4次元固有の様々な現象のため,他の次元と違い4次元の場合は分類には程遠いのが現状である.本研究の主な目的は,4次元多様体の性質を様々な観点から解明することで4次元多様体の分類問題に寄与し,さらに結び目理論への新しい応用を与えることである.具体的には,幾何学的単連結4次元多様体,4次元多様体の微分構造の(非)安定化,枠付き結び目で表示される4次元多様体,の3つのテーマを中心に研究を進める.

Outline of Final Research Achievements

We studied smooth structures of 4-dimensional geometric objects, which are called 4-manifolds. Specifically, under a certain assumption on the cohomology ring, we proved that every closed connected oriented 4-manifold is of mod 2 simple type, giving a partial solution to the mod 2 version of the simple type conjecture posed in 1990s. We also gave a systematic construction of exotic 4-manifolds having equivalent genus functions. This result shows a limitation of genus functions as invariants of smooth structures.

Academic Significance and Societal Importance of the Research Achievements

単純型予想はゲージ理論における懸案の問題であり、その mod 2 版の部分的解決は4次元多様体の Seiberg-Witten 不変量の性質解明において重要である。位相構造の適当な条件の下で、4次元位相多様体上の全ての微分構造に共通する新しい有用な性質を明らかにしたという点にも意義がある。種数関数は4次元トポロジーで 60 年以上にわたって研究されている基本的な研究対象であり、本研究でその不変量としての限界を明らかにしたことは重要である。

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

    (17 results)

All 2024 2023 2022 2021 2020 2019

All Journal Article (1 results) (of which Peer Reviewed: 1 results,  Open Access: 1 results) Presentation (16 results) (of which Int'l Joint Research: 7 results,  Invited: 12 results)

  • [Journal Article] The simple type conjecture for mod 2 Seiberg-Witten invariants2022

    • Author(s)
      Kato Tsuyoshi、Nakamura Nobuhiro、Yasui Kouichi
    • Journal Title

      Journal of the European Mathematical Society

      Volume: - Issue: 12 Pages: 4869-4877

    • DOI

      10.4171/jems/1297

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed / Open Access
  • [Presentation] Genus functions of 4-manifolds and their applications2024

    • Author(s)
      Kouichi Yasui
    • Organizer
      Differential Topology '24 Cork, exotic structure, concordance
    • Related Report
      2023 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] 4次元多様体の微分構造と種数関数2023

    • Author(s)
      安井弘一
    • Organizer
      日本数学会 2023 年度秋季総合分科会
    • Related Report
      2023 Annual Research Report
    • Invited
  • [Presentation] Exotic 4-manifolds and genus functions2023

    • Author(s)
      安井弘一
    • Organizer
      研究集会「4次元トポロジー」
    • Related Report
      2023 Annual Research Report
  • [Presentation] Sums of 4-manifolds, genus functions and their applications2023

    • Author(s)
      Kouichi Yasui
    • Organizer
      Gauge Theory in Kyoto
    • Related Report
      2022 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Sums of 4-manifolds, genus functions and their applications2022

    • Author(s)
      Kouichi Yasui
    • Organizer
      4-Manifolds: From Above and Below
    • Related Report
      2022 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Sums of 4-manifolds, genus functions and their applications2022

    • Author(s)
      安井弘一
    • Organizer
      九州大学金曜トポロジーセミナー
    • Related Report
      2022 Research-status Report
    • Invited
  • [Presentation] Stably exotic pairs of closed 4-manifolds and their applications2021

    • Author(s)
      安井弘一
    • Organizer
      研究集会「4次元トポロジー」
    • Related Report
      2021 Research-status Report
  • [Presentation] Minimal genus functions and constraints on 4-manifolds2020

    • Author(s)
      Kouichi Yasui
    • Organizer
      International Workshop on 4-Manifold Theory and Gauge Theory
    • Related Report
      2020 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Embedded surfaces and the simple type conjecture2020

    • Author(s)
      安井弘一
    • Organizer
      研究集会「4次元トポロジー」
    • Related Report
      2020 Research-status Report
  • [Presentation] Stably exotic 4-manifolds2020

    • Author(s)
      安井 弘一
    • Organizer
      4-Dimensional Topology and Gauge Theory
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Minimal genus functions and smooth structures of 4-manifolds2019

    • Author(s)
      Kouichi Yasui
    • Organizer
      Workshop on low-dimensional topology
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Nonexistence of twists and surgeries generating exotic 4-manifolds2019

    • Author(s)
      Kouichi Yasui
    • Organizer
      Workshop on low-dimensional topology
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Minimal genus functions and smooth structures of 4-manifolds2019

    • Author(s)
      Kouichi Yasui
    • Organizer
      Workshop on Lefschetz Pencils and Low dimensional Topology
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] 4 次元多様体の微分構造と幾何学的単連結性2019

    • Author(s)
      安井 弘一
    • Organizer
      広島大学談話会
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Smooth 4-manifolds and geometric simple connectivity2019

    • Author(s)
      安井 弘一
    • Organizer
      京都大学数学教室談話会
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Stably exotic 4-manifolds2019

    • Author(s)
      安井 弘一
    • Organizer
      研究集会「4次元トポロジー」
    • Related Report
      2019 Research-status Report

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

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