Updated on 2024/04/19

写真a

 
OI Shiho
 
Organization
Academic Assembly Institute of Science and Technology Fundamental Sciences Assistant Professor
Faculty of Science Department of Science Assistant Professor
Title
Assistant Professor
External link

Degree

  • 博士(理学) ( 2020.3   新潟大学 )

Research Interests

  • バナッハ環

  • 等距離写像

  • 保存問題

Research Areas

  • Natural Science / Basic analysis

  • Natural Science / Mathematical analysis

Research History

  • Niigata University   Faculty of Science Department of Science   Assistant Professor

    2020.6

Professional Memberships

 

Papers

  • ISOMETRIES AND HERMITIAN OPERATORS ON SPACES OF VECTOR-VALUED LIPSCHITZ MAPS Reviewed

    Shiho Oi

    Journal of the Institute of Mathematics of Jussieu   1 - 18   2023.11

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    Publishing type:Research paper (scientific journal)   Publisher:Cambridge University Press (CUP)  

    Abstract

    We study hermitian operators and isometries on spaces of vector-valued Lipschitz maps with the sum norm. There are two main theorems in this paper. Firstly, we prove that every hermitian operator on $\operatorname {Lip}(X,E)$, where E is a complex Banach space, is a generalized composition operator. Secondly, we give a complete description of unital surjective complex linear isometries on $\operatorname {Lip}(X,\mathcal {A})$, where $\mathcal {A}$ is a unital factor $C^{*}$-algebra. These results improve previous results stated by the author.

    DOI: 10.1017/s1474748023000415

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  • Isometries, Jordan *-isomorphisms and order isomorphisms on spaces of a unital $C^*$-algebra-valued continuous maps Reviewed

    Shiho OI

    ( B93 )   133 - 141   2023.7

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    Language:English  

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  • Linear preservers on idempotents of Fourier algebras Reviewed

    Ying-Fen Lin, Shiho Oi

    Canadian Mathematical Bulletin   1 - 15   2023.5

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    Publishing type:Research paper (scientific journal)   Publisher:Canadian Mathematical Society  

    Abstract

    In this article, we give a representation of bounded complex linear operators that preserve idempotent elements on the Fourier algebra of a locally compact group. When such an operator is, moreover, positive or contractive, we show that the operator is induced by either a continuous group homomorphism or a continuous group antihomomorphism. If the groups are totally disconnected, bounded homomorphisms on the Fourier algebra can be realized by the idempotent preserving operators.

    DOI: 10.4153/s0008439523000395

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  • Jordan ∗-homomorphisms on the spaces of continuous maps taking values in C∗-algebras Reviewed

    Shiho Oi

    Studia Math.   269 ( no.1. )   107 - 119   2023

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    Language:English   Publishing type:Research paper (scientific journal)  

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  • Tingley's problems on uniform algebras Reviewed

    Osamu Hatori, Shiho Oi, Rumi Shindo Togashi

    Journal of Mathematical Analysis and Applications   503 ( 2 )   125346 - 125346   2021.11

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    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jmaa.2021.125346

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  • A spherical version of the Kowalski-Slodkowski theorem and its applications Reviewed

    Oi Shiho

    Journal of the Australian Mathematical Society   2020

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    Language:English   Publishing type:Research paper (scientific journal)  

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  • Hermitian operators and isometries on algebras of matrix-valued Lipschitz maps Reviewed

    Oi Shiho

    Linear and Multilinear Algebra   68 ( 6 )   1096 - 1112   2020

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    Language:English   Publishing type:Research paper (scientific journal)  

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  • Hermitian operators and isometries on injective tensor products of uniform algebras and C*-algebras Reviewed

    Hatori Osamu, Kawamura Kazuhiro, Oi Shiho

    JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS   472 ( 1 )   827 - 841   2019.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jmaa.2018.11.052

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  • Algebraic reflexivity of isometry groups of algebras of Lipschitz maps Reviewed

    Oi Shiho

    LINEAR ALGEBRA AND ITS APPLICATIONS   566   167 - 182   2019.4

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.laa.2018.12.033

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  • 2-local isometries on function spaces Reviewed

    O.Hatori, S.Oi

    Contemporary Mathematics   737   89 - 106   2019

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:American Mathematical Society  

    DOI: 10.1090/conm/737/14860

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  • Isometries on Banach algebras of vector-valued maps Reviewed

    Hatori Osamu, Oi Shiho

    ACTA SCIENTIARUM MATHEMATICARUM   84 ( 1-2 )   151 - 183   2018

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.14232/actasm-017-558-6

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  • Peculiar homomorphisms between algebras of vector-valued maps Reviewed

    Hatori Osamu, Oi Shiho, Takagi Hiroyuki

    STUDIA MATHEMATICA   242 ( 2 )   141 - 163   2018

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4064/sm8799-6-2017

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  • Hermitian operators on Banach algebras of vector-valued Lipschitz maps (vol 452, pg 378, 2017) Reviewed

    Hatori Osamu, Oi Shiho

    JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS   453 ( 2 )   1151 - 1152   2017.9

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.jmaa.2017.04.058

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  • Hermitian operators on Banach algebras of vector-valued Lipschitz maps Reviewed

    Hatori Osamu, Oi Shiho

    JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS   452 ( 1 )   378 - 387   2017.8

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.jmaa.2017.03.015

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  • Peculiar homomorphisms on algebras of vector-valued continuously differentiable maps Reviewed

    O.Hatori, S.Oi, H.Takagi

    Linear and Nonlinear Analysis   3   101 - 109   2017

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    Language:English   Publishing type:Research paper (scientific journal)  

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  • Homomorphisms between algebras of Lipschitz functions with the values in function algebras Reviewed

    Oi Shiho

    JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS   444 ( 1 )   210 - 229   2016.12

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.jmaa.2016.06.015

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MISC

Presentations

  • Unital surjective linear isometries on Lipchitz algebras taking values in primitive $C^{*}$-algebras

    Shiho OI

    Workshop on Function spaces and related topics  2023.4 

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    Event date: 2023.4

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  • Surjective isometries and Hermitian operators on vector-valued Lipschitz algebras Invited

    Shiho Oi

    2022 Japan-China International Conference on matrix theory with applications  2022.12 

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    Event date: 2022.12

    Language:English   Presentation type:Oral presentation (invited, special)  

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  • C∗ 環に値をとるリプシッツ関数のなすバナッハ環上の等距離写像 Invited

    大井志穂

    第11 回信州関数解析シンポジウム  2022.11 

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    Event date: 2022.11

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

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  • C∗ 環値リプシッツ環の間の Jordan* 同型写像とその応用

    大井志穂

    2022 年度 関数環研究集会  2022.11 

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    Event date: 2022.11

    Language:Japanese   Presentation type:Oral presentation (general)  

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  • Kowalski-S\l odkowskiの定理と2-local等距離写像 Invited

    大井志穂

    第 6 回幾何学的群論ワークショップ  2022.10 

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    Event date: 2022.10

    Language:Japanese  

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  • 2-local isometries on commutative Banach algebras Invited

    Shiho Oi

    Women in Operator Theory  2022.10 

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    Event date: 2022.10

    Language:English   Presentation type:Oral presentation (invited, special)  

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  • C*環に値をとるリプシッツ環上のJordan* 準同型写像

    大井志穂

    日本数学会 2022年度秋季総合分科会  2022.9 

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    Event date: 2022.9

    Presentation type:Oral presentation (general)  

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  • C*環に値をとる連続写像のなすバナッハ環上の保存問題 Invited

    大井志穂

    第69回トポロジ―シンポジウム  2022.8 

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    Event date: 2022.8

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  • Jordan *-homomorphisms on *-algebras of vector-valued continuous maps Invited

    Shiho Oi

    Operators on Banach algebras and related topics, Tarbiat Modares University, Iran  2022.7 

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    Event date: 2022.7

    Language:English   Presentation type:Oral presentation (invited, special)  

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  • Surjective linear isometries on Banach algebras of continuous functions Invited

    Shiho Oi

    Trojan Math Seminar, Troy University  2024.1 

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    Language:English  

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  • Isometries between groups of invertible elements in Fourier-Stieltjes algebras Invited

    Shiho Oi

    Joint Mathematics Meetings 2024 (AMS Special Session on New Faces in Operator Theory and Function Theory)  2024.1 

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    Language:English  

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  • フーリエ環のべき等元を保存する写像

    大井志穂

    2023年度 関数環研究集会  2023.12 

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  • Linear preservers on idempotents of Fourier algebras

    Shiho OI

    Recent Progress in Operator Theory and its Applications (RIMS 共同研究)  2023.11 

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    Language:English  

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  • バナッハ環におけるノルム構造,代数構造,順序構造の関係 Invited

    大井志穂

    日本数学会 秋季総合分科会 2023  2023.9 

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    Language:Japanese   Presentation type:Oral presentation (invited, special)  

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  • Linear operators on Fourier algebras preserving idempotents

    Shiho OI

    The 6th Niigata Seminar  2023.8 

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    Language:English  

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  • バナッハ環上の全射線形等距離写像について

    大井志穂

    東京都立大学・幾何学セミナー  2023.6 

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    Presentation type:Oral presentation (general)  

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  • 行列値リプシッツ環上の 全射線形等距離写像の代数的反射性

    大井志穂

    2023年 日本数学会年会  2023.3 

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    Presentation type:Oral presentation (general)  

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  • C*環に値をとる連続写像のなすバナッハ環上の 等距離写像

    大井志穂

    第8 回山陰基礎論と数学およびその周辺の研究集会  2023.1 

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    Presentation type:Oral presentation (general)  

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  • C*環に値をとる連続写像のなすバナッハ環上のJordan* 同型写像

    大井志穂

    2021年度関数環研究集会  2021.12 

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    Presentation type:Oral presentation (general)  

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  • リプシッツ写像のなすBanach 環の距離構造と代数構造 Invited

    2021年度ジェネラルトポロジーシンポジウム  2021.12 

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    Presentation type:Oral presentation (invited, special)  

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  • Surjective linear isometries on unital C*-algebra valued Lipschitz algebras Invited

    Shiho Oi

    Research on preserver problems on Banach algebras and related topics, 京都大学(数理解析研究所)  2021.10 

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    Presentation type:Oral presentation (invited, special)  

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  • C*環に値をとるリプシッツ環の間の等距離写像 Invited

    大井志穂

    第60 回実函数論・函数解析学合同シンポジウム  2021.9 

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    Presentation type:Oral presentation (invited, special)  

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  • Surjective isometries on Banach algebras of Lipschitz maps taking values in a unital C*-algebra Invited

    Shiho Oi

    the 8th European Congress of Mathematics-8ECM, Minisymposum: Recent Developments on Preservers  2021.7 

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    Presentation type:Oral presentation (general)  

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  • 2-local isometries on commutative Banach algebras

    2021.3 

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    Presentation type:Oral presentation (general)  

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  • Order isomorphisms on spaces of continuous maps

    2020.11 

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    Presentation type:Oral presentation (general)  

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  • 行列環に値をとるLipschitz環の間の全射等距離写像について

    大井志穂

    日本数学会2020年度秋季総合分科会  2020.9 

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    Language:Japanese   Presentation type:Oral presentation (general)  

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  • Reflexivity of isometry groups Invited

    大井志穂

    RIMS共同研究(公開型)「様々な関数空間上の等距離写像の研究」  2020.1 

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    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:京都大学  

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  • 2-local isometries on spaces of continuous functions Invited

    大井志穂

    作用素論・作用素環論研究集会  2019.12 

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    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:神奈川大学・横浜キャンパス  

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  • Hermitian operators on Banach algebras of vector-valued continuous maps

    Oi Shiho

    関数環研究集会  2019.12 

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    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:日本大学理工学部  

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  • 関数空間の間の2-local map について Invited

    大井志穂

    第61 回関東作用素論セミナー  2019.7 

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    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:東洋大学白山キャンパス  

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  • Hermitian operators and surjective isometries on vector-valued Lipschitz spaces Invited International conference

    Oi Shiho

    Women in Operator Theory and its Applications  2019.6 

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    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:University of Lisbon, Portugal  

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  • 2-local maps on spaces of continuous functions

    羽鳥理, 大井志穂

    日本数学会2019 年度年会  2019.3 

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    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:東京工業大学  

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  • Algebraic reflexivity of the group of surjective linear isometries International conference

    Oi Shiho

    関数環研究集会  2018.12 

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    Language:English   Presentation type:Oral presentation (general)  

    Venue:金沢医科大学  

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  • Hermitian operators on spaces of vector-valued Lipschitz maps Invited International conference

    Oi Shiho

    Researches on theory of isometries and preserver problems from a various point of view(RIMS Conference)  2018.2 

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    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Kyoto University  

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  • Surjective linear isometries on vector-valued Lipschitz algebras Invited International conference

    Oi Shiho

    The international meeting on Commutative algebra, Banach algebras (preserver probrem), Hypergroups and their related topics  2016.11 

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    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Nara Chamber of Commerce and Industy  

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  • Peculiar isomorphisms on algebras of Lipschitz maps with values in uniform algebras Invited International conference

    Oi Shiho, Hatori Osamu, Takagi HIroyuki

    The international meeting on Commutative algebra, Banach algebras (preserver probrem), Hypergroups and their related topics  2016.11 

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    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Nara Chamber of Commerce and Industy  

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  • Peculiar homomorphisms on commutative Banach algebras of vector-valued functions Invited International conference

    Oi Shiho, Hatori Osamu, Takagi HIroyuki

    Researches on isometries from various view points (RIMS Workshop)  2016.11 

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    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Kyoto University  

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  • Hermitian operators on Banach algebras of vector-valued Lipschitz maps Invited International conference

    Oi Shiho

    Researches on isometries from various view points (RIMS Workshop)  2016.11 

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    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Kyoto University  

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  • Homomorphisms on vector-valued Banach function algebras

    Oi Shiho, Hatori Osamu, Takagi HIroyuki

    第90 回米沢数学セミナー  2016.7 

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    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:山形大学  

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  • On isometries of vector-valued Lipschitz algebras

    Hatori Osamu, Oi Shiho

    第90 回米沢数学セミナー  2016.7 

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    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:山形大学  

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  • Lipschitz 環の写像に対する代数的反射性

    大井志穂

    つくばセミナー  2016.3 

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    Language:English   Presentation type:Oral presentation (general)  

    Venue:筑波大学  

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  • Lipschitz 環上の準同形写像について Invited

    大井志穂

    第89 回米沢数学セミナー「学術講演会」  2016.2 

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    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:山形大学  

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  • 関数環に値をとるLipschitz 環上の準同形写像について

    大井志穂

    関数環研究集会  2015.12 

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    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:新潟大学  

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  • Peripheral spectrum conditions for triple products of Lipschitz functions on non-compact metric spaces Invited International conference

    Oi Shiho

    International Conference on Preserver Problems and Related Topics  2015.5 

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    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Niigata University  

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Research Projects

  • Isometries on Banach algebras

    Grant number:21K13804

    2021.4 - 2025.3

    System name:Grants-in-Aid for Scientific Research

    Research category:Grant-in-Aid for Early-Career Scientists

    Awarding organization:Japan Society for the Promotion of Science

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\4420000 ( Direct Cost: \3400000 、 Indirect Cost:\1020000 )

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  • Banach空間上のスペクトル保存写像とその応用

    Grant number:20K03650

    2020.4 - 2024.3

    System name:科学研究費助成事業

    Research category:基盤研究(C)

    Awarding organization:日本学術振興会

    三浦 毅, 大井 志穂

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    Grant amount:\4290000 ( Direct Cost: \3300000 、 Indirect Cost:\990000 )

    今年度は主に,局所的な等距離写像(local isometries)に関する研究を行い,いくつかの結果を得た.まず単位閉区間[0,1]上で定義された連続微分可能な複素関数の全体C^1([0,1])に対して,その間の2-local real linear isometryを考察した.一般にTがBanach空間Bの間の2-local isometryであるとは,Bの任意の2点f, gに対して,S(f)=T(f)かつS(g)=T(g)をみたすB上の全射複素線形等距離写像Sが存在することである.この概念は,P.Semrlが導入したlocal mapのアイディアをもとに,Molnarによって提示され,その後2-local isometryの研究は活発になされるようになった.C^1([0,1])には様々なノルムが与えられることが知られる中で,我々は特に|f(0)|+||f'||をノルムとするBanach空間C^1([0,1])に対する2-local real linear isometryを解明した.ここで||g||はgの最大絶対値ノルムである.また,複素平面の単位開円板D上の正則関数で,その導関数がp乗可積分であるもの全体S^p(D)に対して,近似的局所的等距離写像(approximate local isometry)の概念を導入し,その構造を研究した.ここでS^p(D)の間の写像Tがapproximate local isometryであるとは,S^p(D)の任意の2点f, gに対してS^p(D)上の全射複素線形等距離写像の列{U_n}が存在して,n→∞のときノルムの意味でU_n(f)はT(f)に,U_n(g)はT(g)に収束することである.このとき,S^p(D)上の任意のapproximate local isometryは全射等距離写像であることを示すとともに,approximate 2-lolcal isometryの概念も自然な形で導入し,S^p(D)上のapproximate 2-local isometryは全射複素線形等距離写像であることを示した.

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Teaching Experience (researchmap)

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Teaching Experience

  • 先端科学技術総論

    2023
    Institution name:新潟大学

  • 数理解析特別講義

    2023
    Institution name:新潟大学

  • 日本事情自然系A

    2023
    Institution name:新潟大学

  • 理学基礎演習

    2022
    Institution name:新潟大学

  • 数学基礎演習b

    2021
    Institution name:新潟大学

  • 数学講究

    2021
    Institution name:新潟大学

  • 解析学基礎1

    2021
    Institution name:新潟大学

  • 数学基礎演習a

    2021
    Institution name:新潟大学

  • 関数空間特論

    2021
    Institution name:新潟大学

  • 解析学基礎2

    2021
    Institution name:新潟大学

  • 関数空間論

    2021
    Institution name:新潟大学

  • 数学の世界

    2021
    -
    2022
    Institution name:新潟大学

  • 理学スタディ・スキルズ

    2021
    Institution name:新潟大学

  • 専門力アクティブ・ラーニング

    2021
    Institution name:新潟大学

  • 数学演習B

    2020
    Institution name:新潟大学

  • 集合と写像

    2020
    Institution name:新潟大学

  • 数学演習A

    2020
    Institution name:新潟大学

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