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    Talks


    2025 - Future

• Graphs and diffeomorphisms
  International Congress of Mathematicians 2026, Pennsylvania Convention Center, Jul, 2026.
  
  
• グラフ複体と微分同相群
  日本数学会2026年度年会 (特別講演), 東京理科大学神楽坂キャンパス, Mar, 2026.
  
  
• TBA
  トポロジーと数理物理の新展開, 東京大学大学院数理科学研究科, Mar, 2026.
  
  
  
• Smooth bundles of disks from graph homology
  UMN School of Mathematics Colloquium, University of Minnesota, Sep 11, 2025.
  
  
• Brunnian links and Kontsevich graph complex
  One Day Workshop with Rachael Boyd on Algebraic Topology, Kyoto University, Jan 29, 2025.
  
  
  

    2020 - 2024

• Smooth bundles of disks from Kontsevich's graph complex with higher valences
  Spaces of Manifolds: Algebraic and Geometric Approaches, Banff International Research Station, Nov 28, 2023.
  
  
• Smooth bundles of disks from Kontsevich's graph complex with higher valences
  Topology and Geometry of Low-dimensional Manifolds, Shimane University, Nov 3, 2023.
  
  
• Theta-graph surgery for diffeomorphisms of 4-manifolds
  Interactions of 3- and 4-dimensional topology, Online, Mar 10, 2023.
  
  
  
• Recent results: Configuration space integral invariants / Problems (one part of Mini-Series C: diffeomorphism groups)
  BIRS Workshop: Topology in Dimension 4.5, Banff International Research Station, Nov 3, 2022.
  
  
• Theta-graph and diffeomorphisms of some 4-manifolds
  Low-Dimensional Topology & Homeomorphism Groups, Brin Mathematics Research Center (University of Maryland), Sep 8, 2022.
  
  
• Pseudo-isotopies of some spherical 3-manifolds
  New Developments in Four Dimensions, University of Victoria, June 15, 2022.
  
  
  
• Families of diffeomorphisms of some 4-manifolds constructed by graphs
  The 6th China-Japan Geometry Conference, Chongqing University of Technology/Osaka City University/online, Dec 26, 2021.
  
  
• 4次元球面の微分同相群
  大阪大学数学教室談話会(集中講義の第1回), 大阪大学豊中キャンパス, Nov 8, 2021.
  
  
• Claspers and barbells in 4-manifolds
  2021 Georgia Topology Conference, online (University of Georgia), Jun 8, 2021.
  
  
• Theta graph and diffeomorphisms of some 4-manifolds
  微分トポロジーセミナー, online (京都大学数学教室), Jun 1, 2021.
  
  
• Trivalent graphs and diffeomorphisms of some 4-manifolds
  Intelligence of Low-dimensional Topology, online (RIMS), May 21, 2021.
  
  
• Trivalent graphs and diffeomorphisms of some 4-manifolds
  Gauge Theory Virtual, online, Feb 23, 2021.
  
  
• Trivalent graphs and diffeomorphisms of disks
  Algebraic Topology Seminar (Princeton), online, Feb 18, 2021.
  
  
• Result in dimension 4
  Seminar "Configuration space integrals and diffeomorphisms" (Münster), online, Feb 5, 2021.
  
  
  
• Theta-graph and 4-dimensional light bulb problem
  微分トポロジー20, online, Sep 3, 2020.
  
  
• Theta-graph and diffeomorphisms of some 4-manifolds
  ハンドルセミナー'20, online, Jun 25, 2020.
  
  
  

    2015 - 2019

• Families of diffeomorphisms of 4-manifolds via graph surgery I, II
  Symplectic Geometry Seminar, Stanford University, Nov 11, 12, 2019.
  
  
• Some exotic nontrivial elements of the rational homotopy groups of Diff(S^4)
  Topology Seminar, University of Oregon, Nov 5, 2019.
  
  
• Families of diffeomorphisms of 4-manifolds via graph surgery (via Google Hangout from Japan, as my travel was canceled due to typhoon.)
  Spaces of Embeddings: Connections and Applications, BIRS, Banff, Oct 14, 2019.
  
  
• Families of diffeomorphisms of 4-manifolds via graph surgery
  Workshop on 4-manifolds, Max Planck Institute for Mathematics, Bonn, Sep 18, 2019.
  
  
• Talk I: Kontsevich's characteristic classes / II: Morse theoretic propagator and graph counting formula / III: Graph surgery construction of 4-manifold bundles / IV: Computation of the invariant
  HCM Workshop: Automorphisms of Manifolds, Lipschitz lecture hall, Mathematics Center, Bonn, Sep 2, 3, 5, 6, 2019.
  
  
• Families of diffeomorphisms of 4-manifolds via graph surgery
  Four manifolds: Confluence of high and low dimensions, The Fields Institute, Toronto, Jul 8, 2019.
  
  
• 数理科学特別講義VII: Morse理論と多様体・ファイバー束の不変量
  集中講義, 東京大学大学院数理科学研究科, Jun 10-14, 2019.
  
  
• Some exotic nontrivial elements of the rational homotopy groups of Diff(S^4)
  微分トポロジーセミナー, 京都大学数学教室, May 21, 2019.
  
  
• On a 4D analogue of simultaneous normalization of propagators and its applications
  Seminaire de topologie, Institut Fourier, Universite Grenoble Alpes, May 13, 2019.
  
  
• Kontsevich's characteristic classes and diffeomorphisms of the 4-sphere I, II
  Seminaire de topologie, geometrie et algebre, Laboratory of Mathematics Jean Leray, University of Sciences in Nantes, May 2, 9, 2019.
  
  
• 4次元球面の微分同相群 / グラフクラスパーと4次元球面束 / 4次元球面束のKontsevich特性類の計算
  ENCOUNTER with MATHEMATICS, 中央大学理工学部, Mar 16, 2019.
  
  
• Some exotic nontrivial elements of the rational homotopy groups of Diff(S^4) (1), (2)
  Branched Coverings, Degenerations, and Related Topics 2019, 広島大学東広島キャンパス, Mar 7, 8, 2019.
  
  
• Some exotic nontrivial elements of the rational homotopy groups of Diff(S^4)
  OIST Geometry, Topology and Dynamics Seminar, 沖縄科学技術大学院大学(OIST), Jan 24, 2019.
  
  
  
• Diff(S^4)の特性類と族のクラスパー手術
  日本数学会2018年度秋季総合分科会（特別講演）, 岡山大学津島キャンパス, Sep 24, 2018.
  
  
• 4次元Smale予想について (1), (2)
  種々の幾何学的構造と基本群に現れる様々な特性類とその不変量への応用, 国家公務員共済組合連合会 下呂保養所, Aug 4, 5, 2018.
  
  
• Kontsevich's characteristic classes for Diff(S^4)
  信州トポロジーセミナー, 信州大学理学部数学科（松本キャンパス）, Feb 19, 2018.
  
  
  
• On the 4-dimensional smooth Smale conjecture
  トポロジーとコンピュータ 2017, 大阪大学豊中キャンパス, Oct 21, 2017.
  
  
• Garoufalidis-Levine's finite type invariants for Z\pi-homology equivalences of 3-manifolds
  Casson不変量に関わる3次元多様体の不変量, 京都大学数理解析研究所, Jan 27, 2017.
  
  
  
• Morse homotopy and A_infinity structures for surface bundles over S^1
  Workshop on finite type invariants of 3-manifolds, 東京大学大学院数理科学研究科, Mar 31, 2016.
  
  
• Finite type invariants of nullhomologous knots in 3-manifolds by counting graphs
  信州トポロジーセミナー, 信州大学理学部数学科（松本キャンパス）, Mar 15, 2016.
  
  
  
• An invariant of fiberwise Morse functions on surface bundle over S^1 by counting graphs
  日仏共同研究小研究集会（タイヒミュラー空間と写像類群）, 東京大学大学院数理科学研究科, Nov 19, 2015.
  
  
• Finite type invariants of nullhomologous knots in 3-manifolds by counting graphs
  Braids, Configuration spaces and Quantum Topology, 東京大学大学院数理科学研究科, Sep 7, 2015.
  
  
• An invariant of fiberwise Morse functions on surface bundles over S^1 by counting graphs
  リーマン面に関連する位相幾何学, 東京大学大学院数理科学研究科, Aug 25, 2015.
  
  
• On equivariant perturbative invariants in 3-dimension by Morse theory
  RIMS Seminar Topology, Geometry and Algebra of low-dimensional manifolds, 沼津KKR, May 28, 2015.