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SUZUKI Yuhei

Faculty of Science　Mathematics　MathematicsAssociate Professor
Research Center of Mathematics for Social CreativityAssociate Professor

Researcher basic information

■ Degree
  • 博士(数理科学), 東京大学大学院数理科学研究科
■ URL
researchmap URLホームページURL■ Various IDs
Researcher number
  • 20804511
J-Global ID■ Research Keywords and Fields
Research Keyword
  • Discrete groups
  • Topological dynamical systems
  • Operator algebras
Research Field
  • Natural Science, Basic analysis, Operator algebras
■ Educational Organization

Career

■ Career
Career
  • Apr. 2020 - Present
    Hokkaido University, Faculty of Science Department of Mathematics, 准教授
  • Apr. 2017 - Mar. 2020
    Nagoya University, Graduate School of Mathematics, テニュアトラック助教
  • Apr. 2016 - Mar. 2017
    Chiba University, JSPS Research Fellowship for Young Scientists PD
  • Apr. 2013 - Mar. 2016
    University of Tokyo, JSPS Research Fellowship for Young Scientists DC1
Educational Background
  • Apr. 2013 - Mar. 2016, University of Tokyo, Ph.D of Mathematical Sciences
  • Apr. 2011 - Mar. 2013, University of Tokyo, Master of Mathematical Sciences
  • Apr. 2007 - Mar. 2011, Hokkaido University, Science, Mathematics
Committee Memberships
  • Jul. 2024 - Jun. 2028
    Mathematical Society of Japan, Editorial member of `Sugaku’, Society
  • 2025 - 2025
    ICBS(Beijing), Selection committee for the FSA (2025), Functional Analysis and Operator Theory
  • 2024 - 2024
    ICBS(Beijing), Nomination and Selection committee for the FSA, Functional Analysis and Operator Theory
  • Apr. 2021 - Mar. 2022
    Mathematical Society of Japan, Councilor of Hokkaido area, Society

Research activity information

■ Awards
  • Apr. 2026, Hokkaido University, Distinguished researcher
  • Apr. 2025, MEXT (Ministry of Education, Culture, Sports, Science and Technology), The Young Scientists’ Prize
    Researches on non-commutative dynamics and operator algebras
    Yuhei Suzuki
  • Jul. 2023, International Congress of Basic Science (ICBS) (Beijing), Frontiers of Science Awards
    Yuhei Suzuki
  • Sep. 2019, The Mathematical Society of Japan, MSJ Takebe Katahiro Prize for Encouragement of Young Researchers
    Studies on operator algebras arising from topological dynamical systems
    Yuhei SUZUKI
  • Mar. 2016, 東京大学大学院数理科学研究科・研究科長賞
    鈴木悠平
  • Mar. 2011, 財団法人北海道大学クラーク記念財団, クラーク賞
■ Papers
  • Crossed product splitting of intermediate operator algebras via 2-cocycles
    Yuhei Suzuki
    Mathematische Annalen, 394, 2, Springer Science and Business Media LLC, 13 Feb. 2026, [Peer-reviewed], [Lead author, Last author, Corresponding author]
    English, Scientific journal, 36629410
  • Every countable group admits amenable actions on stably finite simple C∗-algebras
    Yuhei Suzuki
    American Journal of Mathematics, 148, 1, 69, 77, Project MUSE, Feb. 2026, [Peer-reviewed], [Lead author, Last author, Corresponding author]
    English, Scientific journal,

    abstract: We give the first examples of (non-amenable group) amenable actions on stably finite simple $\mathrm{C}^\ast$-algebras. More precisely, we give such actions for any countable group in an explicit way. The main ingredients of our construction are the full Fock space of the regular representation and a trace-scaling automorphism.

    , 36629410;12198961
  • Amenable actions on ill-behaved simple C*-algebras
    Yuhei Suzuki
    International Mathematics Research Notices, 2025, 5, 1, 18, Mar. 2025, [Peer-reviewed], [Lead author, Last author, Corresponding author]
    English, Scientific journal
  • Simplicity and tracial weights on non-unital reduced crossed products
    Yuhei Suzuki
    International Journal of Mathematics, 35, 06, World Scientific Pub Co Pte Ltd, 05 Apr. 2024
    Scientific journal, We extend theorems of Breuillard–Kalantar–Kennedy–Ozawa on unital reduced crossed products to the non-unital case under mild assumptions. As a result simplicity of [Formula: see text]-algebras is stable under taking reduced crossed products over discrete [Formula: see text]-simple groups, and a similar result for uniqueness of tracial weight. Interestingly, our analysis on tracial weights involves von Neumann algebra theory.

    Our generalizations have two applications. The first is to locally compact groups. We establish stability results of (non-discrete) [Formula: see text]-simplicity and the unique trace property under discrete group extensions. The second is to the twisted crossed product. Thanks to the Packer–Raeburn theorem, our results lead to (generalizations of) the results of Bryder–Kennedy by a different method.
  • Amenable actions on finite simple C*-algebras arising from flows on Pimsner algebras
    Yuhei Suzuki
    Muenster Journal of Mathematics (Special Issue dedicated to Kirchberg), Mar. 2024, [Peer-reviewed], [Invited], [Lead author, Last author, Corresponding author]
    English, Scientific journal, 36629410;13358512
  • Non-amenable tight squeezes by Kirchberg algebras
    Yuhei Suzuki
    Mathematische Annalen, 382, 1-2, 631, 653, Springer Science and Business Media LLC, Feb. 2022, [Peer-reviewed], [Lead author, Last author, Corresponding author]
    English, Scientific journal, 12198961
  • C*-simplicity has no local obstruction
    Yuhei Suzuki
    Forum of Mathematics, Sigma, 10, 1, 8, Cambridge University Press (CUP), Jan. 2022, [Peer-reviewed], [Lead author, Last author, Corresponding author]
    English, Scientific journal, Abstract

    In 2016, I solved a problem of de la Harpe from 2006: Is there a nondiscrete C$^{\ast }$-simple group? However the solution was not fully satisfactory, as the C$^{\ast }$-simple groups provided (and their operator algebras) are very close to discrete groups. All previously known examples are of this form. In this article I give yet another construction of nondiscrete C$^{\ast }$-simple groups. The statement in the title then follows. This in particular gives the first examples of nonelementary C$^{\ast }$-simple groups (in Wesolek’s sense)., 13358512
  • On characterizations of amenable C*-dynamical systems and new examples
    Narutaka Ozawa; Yuhei Suzuki
    Selecta Mathematica, 27, 5, 1, 29, Springer Science and Business Media LLC, Nov. 2021, [Peer-reviewed]
    English, Scientific journal, AbstractWe show the equivalence of several amenability type conditions for $$\hbox {C}^*$$

    C
    ∗

    -dynamical systems. As an application, based on the Pimsner–Meyer construction, we give a new method to produce amenable actions on simple $$\hbox {C}^*$$

    C
    ∗

    -algebras.
  • Equivariant O2-absorption theorem for exact groups
    Yuhei Suzuki
    Compositio Mathematica, 157, 7, 1492, 1506, Wiley, Jul. 2021, [Peer-reviewed], [Lead author, Last author, Corresponding author]
    English, Scientific journal, We show that, up to strong cocycle conjugacy, every countable exact group admits a unique equivariantly


    $\mathcal {O}_{2}$

    -absorbing, pointwise outer action on the Cuntz algebra


    $\mathcal {O}_{2}$

     with the quasi-central approximation property (QAP). In particular, we establish the equivariant analogue of the Kirchberg


    $\mathcal {O}_{2}$

    -absorption theorem for these groups.
  • Rigid Sides of Approximately Finite-Dimensional Simple Operator Algebras in Non-Separable Category
    Yuhei Suzuki
    International Mathematics Research Notices, 2021, 3, 2166, 2190, Oxford University Press (OUP), 22 Feb. 2021, [Peer-reviewed], [Lead author, Last author, Corresponding author]
    English, Scientific journal, Abstract
    Applying Popa’s orthogonality method to a new class of groups, we construct amenable group factors that are prime and have no infinite-dimensional regular abelian $\ast$-subalgebras. By adjusting Farah–Katsura’s solution of Dixmier’s problem to the von Neumann algebra setting, we obtain the 1st examples of prime approximately finite-dimensional factors and tensorially prime simple AF-algebras. Our results are proved in Zermelo--Fraenkel set theory with the axiom of choice (ZFC), thus in particular answering questions asked by Farah–Hathaway–Katsura–Tikuisis. We also directly determine central sequences of certain crossed products. This concludes the failure of the Kirchberg $\mathcal{O}_{\infty }$-absorption theorem in the non-separable setting.
  • The approximation property and exactness of locally compact groups
    Yuhei Suzuki
    Journal of the Mathematical Society of Japan, 73, 1, 263, 275, Jan. 2021, [Peer-reviewed], [Lead author, Corresponding author]
    Scientific journal
  • On pathological properties of fixed point algebras in Kirchberg algebras
    Yuhei Suzuki
    Proceedings of the Royal Society of Edinburgh: Section A Mathematics, 150, 6, 3087, 3096, Cambridge University Press (CUP), Dec. 2020, [Peer-reviewed], [Lead author, Corresponding author]
    Scientific journal, AbstractWe investigate how the fixed point algebra of a C*-dynamical system can differ from the underlying C*-algebra. For any exact group Γ and any infinite group Λ, we construct an outer action of Λ on the Cuntz algebra ��2 whose fixed point algebra is almost equal to the reduced group C*-algebra ${\rm C}_{\rm r}^* (\Gamma)$. Moreover, we show that every infinite group admits outer actions on all Kirchberg algebras whose fixed point algebras fail the completely bounded approximation property.
  • Almost Finiteness for General Étale Groupoids and Its Applications to Stable Rank of Crossed Products
    Yuhei Suzuki
    International Mathematics Research Notices, 2020, 19, 6007, 6041, Oxford University Press (OUP), 09 Oct. 2020, [Peer-reviewed], [Lead author, Corresponding author]
    Scientific journal, Abstract
    We extend Matui’s notion of almost finiteness to general étale groupoids and show that the reduced groupoid C$^{\ast }$-algebras of minimal almost finite groupoids have stable rank 1. The proof follows a new strategy, which can be regarded as a local version of the large subalgebra argument. The following three are the main consequences of our result: (1) for any group of (local) subexponential growth and for any its minimal action admitting a totally disconnected free factor, the crossed product has stable rank 1; (2) any countable amenable group admits a minimal action on the Cantor set, all whose minimal extensions form the crossed product of stable rank 1; and (3) for any amenable group, the crossed product of the universal minimal action has stable rank 1.
  • Complete descriptions of intermediate operator algebras by intermediate extensions of dynamical systems
    Yuhei Suzuki
    Communications in Mathematical Physics, 375, 2, 1273, 1297, Springer Science and Business Media LLC, Apr. 2020, [Peer-reviewed], [Lead author, Corresponding author]
    English, Scientific journal
  • Simple equivariant C*-algebras whose full and reduced crossed products coincide
    Yuhei SUZUKI
    Journal of Noncommutative Geometry, 13, 4, 1577, 1585, Jan. 2020, [Peer-reviewed], [Lead author, Corresponding author]
    Scientific journal
  • GROUP C*-ALGEBRAS AS DECREASING INTERSECTION OF NUCLEAR C*-ALGEBRAS
    Yuhei Suzuki
    AMERICAN JOURNAL OF MATHEMATICS, 139, 3, 681, 705, Jun. 2017, [Peer-reviewed]
    English, Scientific journal
  • ELEMENTARY CONSTRUCTIONS OF NON-DISCRETE C*-SIMPLE GROUPS
    Yuhei Suzuki
    PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY, 145, 3, 1369, 1371, Mar. 2017, [Peer-reviewed]
    English, Scientific journal
  • Minimal ambient nuclear C*-algebras
    Yuhei Suzuki
    ADVANCES IN MATHEMATICS, 304, 2, 421, 433, Jan. 2017, [Peer-reviewed]
    English, Scientific journal
  • Construction of minimal skew products of amenable minimal dynamical systems
    Yuhei Suzuki
    GROUPS GEOMETRY AND DYNAMICS, 11, 1, 75, 94, 2017, [Peer-reviewed]
    English, Scientific journal
  • Amenable minimal Cantor systems of free groups arising from diagonal actions
    Yuhei Suzuki
    JOURNAL FUR DIE REINE UND ANGEWANDTE MATHEMATIK, 722, 183, 214, Jan. 2017, [Peer-reviewed]
    English, Scientific journal
  • Constructions of amenable dynamical systems and their applications to nuclearity of C*-algebras
    Yuhei SUZUKI
    University of Tokyo, Mar. 2016
    English, Doctoral thesis
  • Group approximation in Cayley topology and coarse geometry, III: Geometric property (T)
    Masato Mimura; Narutaka Ozawa; Hiroki Sako; Yuhei Suzuki
    ALGEBRAIC AND GEOMETRIC TOPOLOGY, 15, 2, 1067, 1091, 2015, [Peer-reviewed]
    English, Scientific journal
  • Haagerup property for C*-algebras and rigidity of C*-algebras with property (T)
    Yuhei Suzuki
    JOURNAL OF FUNCTIONAL ANALYSIS, 265, 8, 1778, 1799, Oct. 2013, [Peer-reviewed]
    English, Scientific journal
■ Other Activities and Achievements
  • 関数解析と行列
    鈴木悠平, 数理科学, 749, Oct. 2025
  • 群と作用素・演算子
    鈴木悠平, 数理科学, 60, 11, Oct. 2022
    Japanese, Introduction commerce magazine
■ Lectures, oral presentations, etc.
  • TBA
    Yuhei Suzuki
    HU-SNU Joint Symposium on Mathematics, 20 Nov. 2026, English, Invited oral presentation
    [Invited]
  • Stabilization theorem and symmetric structure of Cuntz-Pimsner algebras
    Yuhei Suzuki
    Recent Developments in Operator Algebras, Sep. 2026
  • Stabilization theorem and symmetric structure of Cuntz-Pimsner algebras
    Yuhei Suzuki
    Special Week on Operator Algebras, 03 Aug. 2026, English, Invited oral presentation
    [Invited]
  • Stabilization theorem and symmetric structure of Cuntz-Pimsner algebras
    Yuhei Suzuki
    The China-Japan-Korea Conference on Functional Analysis 2026, 30 Jun. 2026, English, Invited oral presentation
    [Invited]
  • Amenability of C*-dynamical systems
    Yuhei Suzuki
    International Congress of Basic Science, 17 Jul. 2025, English, Keynote oral presentation
    36629410, [Invited]
  • Crossed product splitting of intermediate operator algebras via 2-cocycles
    Yuhei Suzuki
    BIRS Workshop, "Group Operator Algebras: Classification, Structure and Rigidity", 26 Sep. 2024, English, Invited oral presentation
    36629410;13358512, [Invited]
  • Crossed product splitting of intermediate operator algebras via 2-cocycles
    Yuhei Suzuki
    Recent Developments in Operator Algebras), 12 Sep. 2024, Japanese, Invited oral presentation
    36629410;13358512, [Invited]
  • Crossed product splitting of intermediate operator algebras via 2-cocycles
    Yuhei Suzuki
    Quantum Theory and Operator Theory, 28 Aug. 2024, English, Invited oral presentation
    36629410, [Invited]
  • Crossed product splitting of intermediate operator algebras via 2-cocycles
    Yuhei Suzuki
    International Congress of Basic Science, BIMSA(Beijing, 18 Jul. 2024, English, Keynote oral presentation
    [Invited]
  • Amenable actions on finite simple C*-algebras arising from flows on Pimsner algebras
    Yuhei Suzuki
    RIMS Conference, 24 Jan. 2024, Japanese, Invited oral presentation
    36629410;13358512, [Invited]
  • C*-simplicity of discrete extensions
    Yuhei Suzuki
    Totally disconnected locally compact groups: local to global, 10 Oct. 2023, English, Invited oral presentation
    36629410;13358512, [Invited]
  • Amenable actions on finite simple C*-algebras arising from flows on Pimsner algebras
    Yuhei Suzuki
    Workshop on Operator Algebras and Applications: Symmetry and Structure, 21 Sep. 2023, English, Invited oral presentation
    36629410;12198961, [Invited]
  • Amenable actions on finite simple C*-algebras arising from flows on Pimsner algebras
    Yuhei Suzuki
    Operator Algebras and Mathematical Physics (Yasu Festa 60), 24 Jul. 2023, English
    36629410;13358512, [Invited]
  • (Non)commutative dynamics and operator algebras
    Yuhei Suzuki
    International Congress on Basic Science(ICBS), 20 Jul. 2023, English, Invited oral presentation
    [Invited]
  • Amenable actions on finite simple C*-algebras arising from flows on Pimsner algebras
    Yuhei Suzuki
    Algebra, Geometry and C*-algebras, ICMS, Edinburgh), 21 Jun. 2023, English, Invited oral presentation
    36629410;13358512, [Invited]
  • Noncommutatibe amenable actions
    Yuhei Suzuki
    MSJ Autumn Meeting 2022 (Talk Invited by Functional Analysis Section), 15 Sep. 2022, Japanese, Invited oral presentation
    [Invited]
  • Noncommutative amenable actions
    Yuhei Suzuki
    Operator algebras and Group Dynamics(CIRM), 18 May 2022, English, Invited oral presentation
    18 May 2022 - 18 May 2022, 13358512, [Invited]
  • Noncommutative amenable actions: characterizations, applications, and new examples
    Yuhei Suzuki
    Symmetry and amenability in operator algebras, 24 Jan. 2022, Japanese, Invited oral presentation
    24 Jan. 2022 - 25 Jan. 2022, 12198961, [Invited]
  • Noncommutative amenable actions: characterizations, applications, and new examples
    Yuhei Suzuki
    Autumn Operator Algebras Program 2021, 17 Nov. 2021, English, Invited oral presentation
    East China Normal University(Zoom), China, 13358512, [Invited], [International presentation]
  • Simplicity and tracial weights on non-unital reduced crossed products
    Yuhei Suzuki
    The 15th HU-SNU Joint Symposium on Mathematics: Operator Algebra, 04 Nov. 2021, English, Oral presentation
    13358512
  • C*-simplicity has no local obstruction
    Yuhei Suzuki
    MSJ Autumn Meeting, 16 Sep. 2021
  • C*-simplicity has no local obstruction
    Yuhei Suzuki
    Operator Algebras Session of the IWOTA, 17 Aug. 2021, English, Invited oral presentation
    [Invited]
  • On discovery of non-commutative amenable actions and recent developments
    Yuhei Suzuki
    Hokkaido University Math. dep. colloquium, 25 Nov. 2020, Japanese, Invited oral presentation
    [Invited]
  • Equivariant O_2-absorption theorem for exact groups
    Yuhei Suzuki
    SNU-HU Math Symposium 2020, 13 Nov. 2020, English, Invited oral presentation
    [Invited]
  • Equivariant O_2-absorption theorem for exact groups
    Yuhei Suzuki
    Recent developments in operator algebras, 07 Sep. 2020, Japanese, Invited oral presentation
    [Invited]
  • Equivariant O_2-absorption theorem for exact groups
    Yuhei Suzuki
    Muenster University, 30 Jun. 2020, English, Invited oral presentation
    [Invited]
  • Amenability of groups, actions, and the weak containment problem
    Yuhei Suzuki
    MATHSCI FRESHMAN SEMINAR 2020, 07 Feb. 2020, Invited oral presentation
    [Invited]
  • Amenable actions on Kirchberg algebras and applications
    Annual Meeting on operator theory & operator algebra theory, 08 Dec. 2019, Invited oral presentation
    [Invited]
  • Amenable actions on Kirchberg algebras and application
    Yuhei Suzuki
    Korean Operator Algebra Seminar 17th, 29 Nov. 2019, Invited oral presentation
    [Invited]
  • Non-amenable tight squeezes by Kirchberg algebras
    Yuhei SUZUKI
    Maximal subgroups and operator subalgebras, 19 Sep. 2019, English, Invited oral presentation
    IMPAN(Poland), [Invited], [International presentation]
  • Non-amenable tight squeezes by Kirchberg algebras
    Yuhei SUZUKI
    Topology and Measure in Dynamics and Operator Algebras, 10 Sep. 2019, English, Invited oral presentation
    BIRS(Canada), [Invited], [International presentation]
  • Complete descriptions of intermediate operator algebras by intermediate extensions of dynamical systems
    Yuhei SUZUKI
    Special Week on Operator Algebras, Jun. 2019, English, Invited oral presentation
    East China Normal University, [Invited], [International presentation]
  • Complete descriptions of intermediate operator algebras by intermediate extensions of dynamical systems
    Yuhei SUZUKI
    Geometric Group Theory Workshop, 06 Mar. 2019, English, Invited oral presentation
    [Invited], [Domestic Conference]
  • Complete descriptions of intermediate operator algebras by intermediate extensions of dynamical systems
    Yuhei SUZUKI
    Barcelona Weekend in Operator Algebras, 17 Nov. 2018, English, Invited oral presentation
    Barcelona, CRM, [Invited], [International presentation]
  • Eigenvalue set for etale groupoids and constructions of distinguished minimal actions
    鈴木悠平
    日本数学会2018年度秋季総合分科会, 26 Sep. 2018, Japanese, Oral presentation
    岡山大学, [Domestic Conference]
  • Complete descriptions of intermediate operator algebras by intermediate extensions of dynamical systems
    鈴木悠平
    作用素環論の最近の進展, 05 Sep. 2018, Japanese, Oral presentation
    京都大学, [Invited], [Domestic Conference]
  • 亜群のalmost finitenessと接合積の安定階数
    鈴木悠平
    作用素論・作用素環論研究集会, 17 Nov. 2017, Japanese, Oral presentation
    立命館大学, [Invited], [Domestic Conference]
  • 極小拡大の接合積C*環の純無限性について
    鈴木悠平
    2017年度秋季総合分科会, 13 Sep. 2017, Japanese, Oral presentation
    山形大学, [Domestic Conference]
  • Almost finiteness for general etale groupoids and its applications to stable rank of crossed products
    鈴木悠平
    RIMS研究集会 作用素環論の最近の進展, 04 Sep. 2017, English, Oral presentation
    京都大学, [Invited], [Domestic Conference]
  • Elementary constructions of non-discrete C*-simple groups
    鈴木悠平
    2016年度秋季総合分科会, 17 Sep. 2016, Japanese, Oral presentation
    関西大学, [Domestic Conference]
  • Construction of minimal skew products of amenable minimal dynamical systems
    鈴木悠平
    2016年度秋季総合分科会, 17 Sep. 2016, Japanese, Oral presentation
    関西大学, [Domestic Conference]
  • 離散じゃないC*単純群の簡単な作り方
    鈴木悠平
    第51回関数解析研究会, 28 Aug. 2016, Japanese, Oral presentation
    群馬大学草津セミナーハウス, [Domestic Conference]
  • Minimal ambient nuclear C*-algebras
    Yuhei SUZUKI
    Classification of operator algebras: complexity, rigidity, and dynamics, 05 Apr. 2016, English, Oral presentation
    Mittag-Leffler Institute (Sweden), [Invited], [International presentation]
  • Minimal ambient nuclear C*-algebras
    鈴木悠平
    エルゴード理論と群論に関連した作用素環論における諸問題の研究, 27 Jan. 2016, Japanese, Oral presentation
    京都大学, [Invited], [Domestic Conference]
  • Group C*-algebras as decreasing intersection of nuclear C*-algebras
    Yuhei SUZUKI
    Young Mathematicians in C*-Algebras, 17 Aug. 2015, English, Oral presentation
    University of Copenhagen, [Invited], [International presentation]
  • Construction of minimal skew products of amenable minimal dynamical systems
    Yuhei SUZUKI
    Workshop on C*-algebras: Geometry and Actions, 14 Jul. 2015, English, Oral presentation
    University of Muenster, [Invited], [International presentation]
  • Construction of minimal skew products of amenable minimal dynamical systems
    Yuhei SUZUKI
    Mathematical Symposium ENS Lyon-Todai, 25 Jun. 2015, English, Oral presentation
    ENS Lyon, [Invited], [International presentation]
  • 従順極小位相力学系の極小斜積拡大の構成
    鈴木悠平
    テニュアトラックミニ研究集会, 26 Mar. 2015, Japanese, Oral presentation
    お茶の水女子大学, [Invited], [Domestic Conference]
  • Group C*-algebras as decreasing intersection of nuclear C*-algebras
    鈴木悠平
    関西作用素環セミナー, 30 Nov. 2014, Japanese, Oral presentation
    白浜, [Invited], [Domestic Conference]
  • Amenable minimal Cantor systems of free groups arising from diagonal actions
    Yuhei SUZUKI
    日本数学会2014年度秋季総合分科会, 27 Sep. 2014, Japanese, Oral presentation
    広島大学, [Domestic Conference]
  • Realization of group C*-algebras with approximation property as decreasing intersection of Cuntz algebras O_2
    Yuhei SUZUKI
    作用素環論の最近の進展, 09 Sep. 2014, English, Oral presentation
    京都大学, [Invited], [Domestic Conference]
  • Realization of hyperbolic group C*-algebras as decreasing intersection of Cuntz algebras O_2
    Yuhei SUZUKI
    Classification, STructure, Amenability and Regularity (CStar) Conference, 02 Sep. 2014, English, Oral presentation
    University of Glasgow, [Invited], [International presentation]
  • Ambient nuclear C*-algebra of reduced free group C*-algebra smaller than boundary algebra
    鈴木悠平
    2014年度関数解析研究会, 20 Aug. 2014, English, Oral presentation
    [Domestic Conference]
  • Amenable minimal Cantor systems of free groups arising from diagonal actions
    Yuhei SUZUKI
    ICM Satellite Conference on Operator Algebras and Applications, 09 Aug. 2014, English, Oral presentation
    [Domestic Conference]
  • Some isomorphism theorems of O_2 (Theorem of Elliott and Rørdam)
    Yuhei SUZUKI
    Summer Camp on Operator Algebras, 19 Jul. 2014, English, Oral presentation
    小樽, [Invited], [International presentation]
  • Amenable minimal Cantor systems of free groups arising from diagonal actions
    Yuhei SUZUKI
    Operator Spaces, Locally Compact Quantum Groups and Amenability, 30 May 2014, English, Oral presentation
    Fields institute（Canada, Toronto), [Invited], [International presentation]
  • Amenable minimal Cantor systems of free groups arising from diagonal actions
    Yuhei SUZUKI
    East Asian Core Doctoral Forum on Mathematics, 24 Jan. 2014, English, Oral presentation
    [Invited], [International presentation]
  • Amenable minimal Cantor systems of free groups arising from diagonal actions
    Yuhei SUZUKI
    Metric geometry and analysis, 12 Dec. 2013, English, Oral presentation
    京都大学, [Invited], [International presentation]
  • Amenable minimal Cantor systems of free groups arising from diagonal actions
    Yuhei SUZUKI
    Metric geometry and analysis, 03 Dec. 2013, Japanese, Oral presentation
    [Invited], [Domestic Conference]
  • C*環のHaagerup propertyとproperty (T)をもつC*環の剛性
    鈴木悠平
    日本数学会2013年度秋季総合分科会, 26 Sep. 2013, Japanese, Oral presentation
    [Domestic Conference]
  • Cantor集合上の自由群の従順極小力学系とC*環
    鈴木悠平
    2013年度関数解析研究会, 19 Sep. 2013, Japanese, Oral presentation
    [Domestic Conference]
  • C*環のHaagerup propertyとproperty (T)をもつC*環の剛性
    鈴木悠平
    RIMS研究集会 作用素環論の最近の進展, 11 Sep. 2013, Japanese, Oral presentation
    京都大学, [Invited], [Domestic Conference]
  • Cantor集合上の自由群の従順極小力学系とC*環
    鈴木悠平
    FMSP Tambara Student Session, 03 Sep. 2013, Japanese, Oral presentation
    [Invited], [Domestic Conference]
  • Haagerup property for C*-algebras and rigidity of C*-algebras with property (T)
    Yuhei SUZUKI
    The Asian Mathematical Conference 2013, 02 Jul. 2013, English, Oral presentation
    [Invited], [International presentation]
  • C*環のHaagerup propertyとproperty (T)をもつC*環の剛性
    鈴木悠平
    関西作用素環セミナー, 08 Jun. 2013, Japanese, Oral presentation
    [Invited], [Domestic Conference]
  • Haagerup property について
    鈴木悠平
    第9回数学総合若手研究集会, 04 Mar. 2013, Japanese, Oral presentation
    [Domestic Conference]
  • C*環のHaagerup propertyとproperty (T)をもつC*環の剛性
    鈴木悠平
    作用素環の集い, 20 Feb. 2013, Japanese, Oral presentation
    [Invited], [Domestic Conference]
  • An example of non-isomorphic C*-algebras whose universal enveloping von Neumann algebras are isomorphic
    Yuhei SUZUKI
    2011年度関数解析研究会, 10 Sep. 2011, Japanese, Oral presentation
    [Domestic Conference]
■ Syllabus
  • 微分積分学Ⅰ, 2024年, 学士課程, 全学教育
  • 微分積分学Ⅱ, 2024年, 学士課程, 全学教育
  • 解析学基礎, 2024年, 学士課程, 理学部
  • 解析学基礎演習, 2024年, 学士課程, 理学部
  • 解析学基礎演習Ｂ, 2024年, 学士課程, 理学部
  • 解析学基礎Ｂ, 2024年, 学士課程, 理学部
■ Affiliated academic society
  • THE MATHEMATICAL SOCIETY OF JAPAN
■ Research Themes
  • Operator algebras of locally compact groups and their structures
    Grant-in-Aid for Early-Career Scientists
    Apr. 2022 - Mar. 2025
    鈴木 悠平
    JSPS, 若手研究, Hokkaido University, Principal investigator, 22K13924
  • 漸近的中心性質を用いたC*力学系および付随するC*接合積の構造解析
    Grant-in-Aid for Early-Career Scientists
    Apr. 2019 - Mar. 2023
    鈴木悠平
    JSPS KAKENHI, Principal investigator, Competitive research funding
  • 部分環族を用いた極小位相力学系の接合積の構造解析
    Grant-in-Aid for Research Activity start-up
    Aug. 2017 - Mar. 2019
    Yuhei SUZUKI
    JSPS: Kakenhi, Principal investigator, Competitive research funding
  • Ｃ＊環論を用いた自由群の位相力学系の研究
    科学研究費助成事業
    01 Apr. 2013 - 31 Mar. 2016
    鈴木 悠平
    前年度の研究で得られた「近似性質を持つ群C*環が核型C*環の減少交叉として得られる」という定理に触発されて，核型でないC*環がどの程度まで“きつい”核型包囲環をもちうるか研究した．私はこの問題にカントール系という対象から研究に取り組み，無限自由積群の群C*環について最良の解を得た．つまり，近似性質をもつ無限自由積群（たとえば無限階の自由群）の被約群C*環に対して，包含の間に非自明な部分C*環がまったく存在しない核型包囲環を構成することができた．近年のC*環の分類理論のめざましい発展は，核型C*環に関するまったく非自明な，信じがたい埋め込みや同型の存在を示している．我々の構成した核型包囲環も分類理論の守備範囲にあるC*環(Kirchberg環)である．そのため，著しく性質の異なる部分環でありながら，中継する部分環をまったくもたないものが存在したことは驚きであると言えるだろう．
    このような問題はvon Neumann環の場合には30年以上前から現在に至るまで，Sorin Popaによるbreakthroughを祖として研究されている「極大単射部分環を探す」という問題と同値である．今回得られた成果は単に極小であるというだけでなく，部分間そのものが存在せず，von Neumann環で知られている結果よりもはるかに強い．そのためC*環の研究者のみならずvon Neumann環の研究者の関心を集めることができた．
    日本学術振興会, 特別研究員奨励費, 東京大学, 13J07810
■ Academic and Social Contribution Activities/Other
Social Contribution Activities
  • JMO夏季セミナー
    21 Aug. 2018 - 21 Aug. 2018
    Lecturer
    数学オリンピック財団
  • NHKカルチャー「数学散策」
    26 May 2018 - 26 May 2018
    Lecturer
    NHK文化センター名古屋教室
  • 2017年度名古屋大学数学公開講座
    14 Oct. 2017 - 28 Oct. 2017
    Lecturer
    名古屋大学
  • 数学アゴラ
    02 Aug. 2017 - 04 Aug. 2017
    Lecturer
    名古屋大学