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1998 Fiscal Year Final Research Report Summary

Research of inequalities of matrix algebra using analytic method

Research Project

Project/Area Number 09640143
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 解析学
Research InstitutionHOKKAIDO UNIVERSITY OF EDUCATION

Principal Investigator

OSADA Masayuki  Sapporo College, Assistant Professor, 教育学部札幌校, 助教授 (10107229)

Co-Investigator(Kenkyū-buntansha) KOMURO Naoto  Asahikawa College, Assistant Professor, 教育学部旭川校, 助教授 (30195862)
NISIMURA Jun-ichi  Sapporo College, Assistant Professor, 教育学部札幌校, 助教授 (00025488)
HASEGAWA Izumi  Sapporo College, Professor, 教育学部札幌校, 教授 (50002473)
SAKURADA Kuninori  Sapporo College, Professor, 教育学部札幌校, 教授 (30002463)
Project Period (FY) 1997 – 1998
Keywordsunitary rho dilation / operator radius / Schur product / Holder type inequality
Research Abstract

1 It is considered many (quasi-)norms on the space of all n*n complex matrices. The rho radius omega_<rho>(.) is one of them. In this research, we will characterize this norm in the case of 2 * 2 matrices by using the theory of complex functions, and apply it to calculation of the rho-radius for some matrices. The main result is the following : Let a, b *D : ={z*C||z|<less than or equal> 1}. Then for rho <greater than or equal> A=[a c 0 b] is a rho-contraction if a
|c|<@D12@>D1+|a-b|<@D12@>D1 <less than or equal> inf|<@D7{rho+(rho)azeta}{rho+(-rho)bzeta}-ab|zeta<@D12@>D1(/)5 pizet
2 Besides of usual mulpiplication, entrywise product (it is called Schur product) or matrices is considered. We had Holder type inequality for p-radius with respect to Schur product as following : Let 0<rho0<rho1<*. Then for any non-negative matrices A, B,
omega_<rho>(A^<(alpha)> o B^<(1-alpha>) <less than or equal> omega_<rho0>(A)^<alpha>_<rho1>(B)^<1-alpha> (0<alpha<1 ; alphazeta0+(1-alpha)zeta1).

  • Research Products

    (6 results)

All Other

All Publications (6 results)

  • [Publications] T.Ando and K.Okubo: "Ho^<・・>lder-type inequalities associated with operator radii and Schur products" Linear and Multilinear Algebra. 43. 53-61 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Nakazi and K.Okubo: "ρ-contraction and 2×2 matrix" Linear Algebra and its Application. 283. 165-169 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Nakazi and K.Okubo: "Generalized numerical radius and unitary ρ-dilation" Mathematica Japonica. (to appear).

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Ando and K.Okubo: "Holder-type inequalities associated with operator radii and Schur products" Linear and Multilinear Algebra. 43. 53-61 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Nakazi and K.Okubo: "rho-contraction and 2*2 matrix" Linear Algebra and its Application. 283. 165-169 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Nakazi and K.Okubo: "Generalized numerical radius and unitary rho-dilation" Mathematica Japonica. (to appear).

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1999-12-08  

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