• Title/Summary/Keyword: Banach Algebra

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A Note on Hermitian Elements of a Banach Algebra

  • Kim, Gwang-Hui
    • Journal of the Chungcheong Mathematical Society
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    • v.1 no.1
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    • pp.33-41
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    • 1988
  • In this paper, the abelian property of Hermitian elements holds not generally in Banach algebra, but in the case that some conditions satisfy, they are abelian. By using property of [1], [2], the Hermitian elements a and b in Banach algebras have been shown that ab = ba.

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ON THE SPECTRAL RADIUS AND INVERTIBILITY OF CERTAIN ELEMENTS IN BANACH ALGEBRA

  • Park, Kyon-Hong;Kim, Byung-Do
    • Journal of applied mathematics & informatics
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    • v.4 no.1
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    • pp.299-308
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    • 1997
  • In this paper we show that the limit of a convergent in-vertible sequence in the set of invertible elements Inv(A) in a Banach algebra A under a certain conditions is invertible and we investigate some properties of the spectral radius of banach algebra with unit.

CONTINUOUS DERIVATIONS OF NONCOMMUTATIVE BANACH ALGEBRA

  • Park, Kyoo-Hong;Jung, Yong-Soo
    • Journal of applied mathematics & informatics
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    • v.7 no.1
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    • pp.319-327
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    • 2000
  • In this paper we investigate the conditions for derivations under which the Singer-Wermer theorem is true for noncommutative Banach algebra A such that either [[D(x),xD(x)] ${\in}$ rad(A) for all $x{\in}$A or $D(x)^2$x+xD(x))$^2$${\in}$rad(A) for all $x{\in}$A, where rad(A) is the Jacobson radical of A, then $D(A){\subseteq}$rad(A).

ON THE RANGE OF DERIVATIONS

  • Chang, Ick-Soon
    • Journal of the Chungcheong Mathematical Society
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    • v.12 no.1
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    • pp.187-191
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    • 1999
  • In this paper we will show that if [G(y), x]D(x) lies in the nil radical of A for all $x{\in}A$, then GD maps A into the radical, where D and G are derivations on a Banach algebra A.

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RESULTS ON THE RANGE OF DERIVATIONS

  • Jung, Yong-Soo
    • Bulletin of the Korean Mathematical Society
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    • v.37 no.2
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    • pp.265-272
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    • 2000
  • Let D be a derivation on an Banach algebra A. Suppose that [[D(x), x], D(x)] lies in the nil radical of A for all $x{\;}{\in}{\;}A$. Then D(A) is contained in the Jacobson radical of A.

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