Ibaraki University's
Graduate School of Science and Engineering (Engineering)
Common Section

Associate Professor

### HOSOKAWA Takuya

#### Career

1. 高麗大学 大学院 基礎科学科 研究教授(ポスドク研究員) 2008/09/01-2009/03/31
2. 茨城大学工学部 講師 2009/04/01-2011/03/31
3. 茨城大学工学部 准教授 2011/04/01-Present

1. Kyoto University Faculty of Science 理学科 1998/03/31 Graduated
2. Kyoto University Graduate School, Division of Natural Science 数学・数理解析専攻 Doctor prophase 2000/03/31 Completed
3. Niigata University Graduate School of Science and Technology 情報理工学専攻 Doctor later 2003/03/31 Completed

1. Chaotic behavior of dinamics by bounded linear operators, Master thesis, Kyoto University Kyoto University 2000/03
2. Composition operators on the Hardy space H^2 and H^∞, Thesis, Niigata University Niigata University 2003/03

#### Current state of research and teaching activities

 Analytic Function Space Theory and Operator Theory.

#### Research Areas

1. Basic Analysis

#### Research keywords

1. Analytic Function Space Theory and Operator Theory. Composition operators and weighted composition operators on the Hardy, Bergman, Bloch spaces.

#### Subject of research

1. Differences of two composition operators on analytic function spaces We characterize some properties of differences of two composition operators on analytic function spaces in terms of Function Theoritic properties of their symbols, hyperbolic metric, and hyperbolic derivative. 2000/04-Present

#### Papers

1. Research paper (scientific journal) Joint Weighted composition operators between Hilbert spaces of analytic functions in the operator norm and Hilbert-Schmidt norm topologies Takuya Hosokawa, Keiji Izuchi, Sh\^{u}ichi Ohno Journal of Mathematical Analysis and Applications 421/ 2, 1546-1558 2015
2. Research paper (scientific journal) Joint Some remarks on operator equation $C_\varphi = C_\psi X$ Takuya Hosokawa, Michio Seto Nihonkai Mathematical Journal 25/ 2, 85-91 2014
3. Research paper (scientific journal) Joint Differences of weighted composition operators from $H^\infty$ to Bloch space Takuya Hosokawa, Sh\^{u}ichi Ohno Taiwanese Journal of Mathematics 16/ 6, 2093-2105 2012/12
4. Research paper (scientific journal) Joint Linear Combinations of Composition Operators on the Bloch spaces Takuya Hosokawa, Pekka Nieminen, Sh\^{u}ichi Ohno Canadian Journal of Mathematics 63/ 4, 862-877 2011
5. Research paper (scientific journal) Joint Hilbert-Schmidt differences of composition operators on the Bergman space Boo Rim Choe,Takuya Hosokawa, Hyungwoon Koo Mathematische Zeitschrift 269, 751-775 2011

#### Research presentations

1. Oral presentation(invited, special) Linear combinations of composition operators on H^∞ and the Bloch space ２０１３年作用素論・作用素環論研究集会 2013/11/24
2. Oral presentation(general) Differences of weighted composition operators from H∞ to the Bloch space 2013日本数学会秋季総合分科会 2013/09/25
3. Oral presentation(general) Some notes on composition operators on the Bloch space 第21回宮代セミナー 2012/10/31
4. Oral presentation(general) Differences of weighted composition operators from the Bloch space to H∞ 2012 日本数学会 秋季総合分科会 2012/09/20
5. Oral presentation(general) Differences of weighted composition operators between H∞ and the Bloch spaces Functional Analysis Seminar 2012/08/28

#### Alloted class

1. Mathematical Analysis I
2. Applied Mathematics I
3. Linear Algebra I