gou HIRASAWA - My portal

Profile Information

Affiliation: Professor, Graduate School of Science and Engineering (Engineering) Common Section, Ibaraki University

Degree: 博士（理学）(Mar, 1999, 新潟大学)

Researcher number: 10434002
J-GLOBAL ID: 200901016700024204
researchmap Member ID: 6000003569

Research Interests

semiclosed operator, q-metric, semiclosed subspace, operator range, de Branges space, invariant subspace

Research Areas

Natural sciences / Basic analysis / Basic Analysis

Research History

Education

Apr, 1996 - Mar, 1999

情報理工学, Graduate School, Division of National Science and Technology (except Gakushuin University, Konan University), Niigata University

Papers

Selfadjoint operators and symmetric operators

Go Hirasawa

Acta Scientiarum Mathematicarum, 82(3-4) 529-543, 2016 Peer-reviewed
A characterization of the stability of a system of the Banach space valued differential equations

Takeshi Miura, Go Hirasawa, Sin-Ei Takahasi, Takahiro Hayata

Math.Inequal.Appl., 16(3) 717-728-728, 2013 Peer-reviewedLast author
Isometries and maps compatible with inverted Jordan triple products on groups

Hatori, Osamu; Hirasawa, Go; Miura, Takeshi; M'olnar, Lajos

Tokyo J.Math., 35(2) 385-410-410, 2012 Peer-reviewedLast author
The Hyers-Ulam and Ger type stabilities of the first order linear differential equations

Miura Takeshi; Hirasawa Go

Optim.Appl., 52 191-199-199, 2012 Peer-reviewedLast author
On the Butler-Rassias functional equation and its generalized Hyers-Ulam stability

Miura Takeshi; Hirasawa Go; Hayata Takahiro

Otim.Appl., 52 201-206-206, 2012 Peer-reviewedLast author
A note on the stability of an integral equation

Miura Takeshi; Hirasawa Go;Takahasi Sin-Ei; Hayata Takahiro

Optim. Appl., 52 207-222-222, 2012 Peer-reviewedLast author
A metric for unbounded linear operators in a Hilbert space

G.Hirasawa

Integr.Equ.Ope.Theroy, 70(3) 363-378-378, 2011 Peer-reviewed
Additively spectral-radius preserving surjections between ,unital semisimple commutative Banach algebras

Osamu Hatori, Go Hirasawa, Takeshi Miura

Cent.Eur.J.Math., 8(3) 597-601-601, 2010 Peer-reviewedLast author
A generalization of the Banach Stone theorem for commutative Banaca algebras

G.Hirasawa, T.Miura, R.Shindo

Nihonkai Math. J, 21(2) 105-114, 2010 Peer-reviewedLast author
A polynomially spectral preserving map between uniform algebras

G.Hirasawa, H.Oka

Nihonkai Math.J., 21(2) 115-119, 2010 Peer-reviewedLead author
The q-deformed normal operator and its corresponding contraction

Far East J. Math. Sci., 46(2) 101-106, 2010 Peer-reviewed
Algebraic properties of the distance between Sobolev spaces

Int. J. Funct. Anal. Oper. Theory Appl., 2(2) 181-114, 2010
A perturbation of normal operators on a Hilbert space

Miura, Takeshi;Uchiyama, Atsushi;Oka, Hirokazu;Hirasawa, Go;Takahasi, Sin-Ei;Niwa, Norio

Nonlinear Funct. Anal. Appl., 13(2) 291-297, 2008 Peer-reviewedLast author
A topology for semiclosed operators in a Hilbert space

Go Hirasawa

Acta Sci.Math.(Szeged), 73 271-282, Mar 31, 2007 Peer-reviewed
Superstability of multipliers and ring derivations on Banach algebras

Miura Takeshi, Oka Hirokazu, Go Hirasawa, Sin-ei Takahasi

Banach J.Math.Anal., 1(1) 125-130-130, 2007 Peer-reviewedLast author
A perturbation of ring derivations on Banach algebras

Takeshi Miura, Go Hirasawa, Sin-Ei Takahasi

J.Math.Anal.Appl., 319(2) 522-530-530, 2006 Peer-reviewedLast author
HYERS-ULAM STABILITY OF A CLOSED OPERATOR IN A HILBERT SPACE

Go Hirasawa, Takeshi Miura

Bull. Korean Math. Soc., 43(1) 107-117-117, 2006 Peer-reviewedLead author
Note on the Hyers-Ulam-Rassias stability of the first order linear differential equation

Miura Takeshi, Go Hirasawa, Sin-ei Takahasi

Nonlinear Funct.Anal.Appl., 11(5) 851-858, 2006 Peer-reviewedLast author
HYERS-ULAM-RASSIAS STABILITY OF JORDAN HOMOMORPHISMS ON BANACH ALGEBRAS

Takeshi Miura, Sin-Ei Takahasi, Go Hirasawa

J.Ineq.and Appl., 4(4) 435-441, 2005 Peer-reviewedLast author
A SYMMETRIC OPERATOR AND ITS KAUFMAN'S REPRESENTATION

Go Hirasawa

Per.Math.Hung., 49 43-47, 2004 Peer-reviewed

Misc.

A partially ordered set of invariant semiclosed subspaces

Go Hirasawa

2256, Jun, 2023
Some problems for semiclosed subspaces

Go Hirasawa

RIMS kokyuroku, 2125 72-81, Aug, 2019
A method of diminishing intervals and semiclosed subspaces

Go Hirasawa

RIMS Kokyuroku, 1996 113-120, Apr, 2016
Spectral radii conditions for isomorphisms between unital semisimple commutative Banach algebras

Hirasawa, Go; Miura, Takeshi; Takagi, Hiroyuki

Contemp.Math., 547 125-134-134, 2011 Peer-reviewedLast author
Multiplier の摂動とその存在

三浦毅, 平澤剛, 髙橋眞映

RIMS kokyuroku, 1452 96-102, Oct, 2005 Last author
Banach 環上のJordan homomorphism とその安定性

三浦毅, 髙橋眞映, 平澤剛

RIMS kokyuroku, 1365 48-56, Apr, 2004 Last author
Quotients of Bounded Linear Operators and Some Applications

Go Hirasawa

学位論文, Mar, 1999 Peer-reviewed
A Note on Quotients of Bounded Operators

Saichi Izumino, Go Hirasawa

富山大学教育学部紀要, 49 1-6, 1996

Presentations

Tensor products of semiclosed operators

Dec 9, 2023
半閉作用素の弱共役性について

関数環研究集会, Nov 13, 2022
A partially ordered set of invariant semiclosed subspaces

Oct 27, 2022
Some problems for semiclosed subspaces

Go Hirasawa

京都大学数理解析研究所 RIMS 共同研究（公開型）「保存問題としての等距離写像とその周辺」, Jan 29, 2019
半閉部分空間の path について

第５回日立解析学セミナー, Mar 8, 2018
Another approach to a self-adjointness of operators with a Kato-Rellich potential

2016 Conference on Function Algebras, Dec 2, 2016
A method of diminishing intervals and semiclosed subspaces

平澤剛

京都大学数理解析研究所 RIMS研究集会「順序と幾何による作用素の構造研究と関連する話題」, Nov 11, 2015 Invited
L owner 関数による値域のある性質について

関数環研究集会, Dec 12, 2013
Lowner 関数による値域のある性質について

関数環研究集会, Dec 12, 2013
代数的次元と不変部分空間について

富山解析セミナー2013, Oct 5, 2013
半閉部分空間から閉部分空間へ

解析学セミナー, Mar 7, 2013
ラプラシアンの摂動と距離について

富山解析セミナー2012, Oct 6, 2012
自己共役作用素の半径の最良性について

つくばセミナー, Mar 5, 2012
自己共役作用素の半径の計算方法について

関数環研究集会, Dec 1, 2011
自己共役作用素に関連する半径について

富山解析セミナー2011, Oct 8, 2011
半閉部分空間に関連する諸問題について

つくばセミナー, Mar 7, 2011
A selfadjointness of a given symmetric operator

The 19th Miyashiro Seminar, Jan 8, 2011
Characterizations for extremal extensions

関数環研究集会, Nov 29, 2010
The metric between Sobolev spaces

The Sixth Conference on Function Spaces SIUE 2010, May 21, 2010
q-deformed normal operator and its corresponding contraction

Go Hirasawa

Takahasi International Conference, Mar 21, 2010

Professional Memberships

日本数学会

Research Projects

不変な半閉部分空間の研究

科学研究費助成事業, 基盤研究（C）（一般）, Apr, 2020 - Mar, 2023

平澤剛
選択関数に基づいた不変部分空間問題の位相解析的・幾何的な構造の研究

科学研究費助成事業, 挑戦的萌芽研究, Apr, 2016 - Mar, 2019

平澤剛
DeBranges空間論を用いた半閉作用素の位相解析的研究

科学研究費助成事業, Grant-in-Aid for Scientific Research(C), Apr, 2012 - Mar, 2015