• Title/Summary/Keyword: C-algebras

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WIENER-HOPF C*-ALGEBRAS OF STRONGL PERFORATED SEMIGROUPS

  • Jang, Sun-Young
    • Bulletin of the Korean Mathematical Society
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    • v.47 no.6
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    • pp.1275-1283
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    • 2010
  • If the Wiener-Hopf $C^*$-algebra W(G,M) for a discrete group G with a semigroup M has the uniqueness property, then the structure of it is to some extent independent of the choice of isometries on a Hilbert space. In this paper we show that if the Wiener-Hopf $C^*$-algebra W(G,M) of a partially ordered group G with the positive cone M has the uniqueness property, then (G,M) is weakly unperforated. We also prove that the Wiener-Hopf $C^*$-algebra W($\mathbb{Z}$, M) of subsemigroup generating the integer group $\mathbb{Z}$ is isomorphic to the Toeplitz algebra, but W($\mathbb{Z}$, M) does not have the uniqueness property except the case M = $\mathbb{N}$.

ON DERIVATIONS IN NONCOMMUTATIVE SEMISIMPLE BANACH ALGEBRAS

  • Jung, Yong-Soo
    • Bulletin of the Korean Mathematical Society
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    • v.35 no.3
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    • pp.583-590
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    • 1998
  • The purpose of this paper is to prove the following results: Let A be a noncommutative semisimple Banach algebra. (1) Suppose that a linear derivation D : A $\to A$ is such that [D(x),x]x=0 holds for all $x \in A$. Then we have D=0. (2) Suppose that a linear derivation $D:A\to A$ is such that $D(x)x^2 + x^2D(x)=0$ holds for all $x \in A$. Then we have C=0.

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A FAMILY OF QUANTUM MARKOV SEMIGROUPS

  • Ahn, Sung-Ki;Ko, Chul-Ki;Pyung, In-Soo
    • Communications of the Korean Mathematical Society
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    • v.20 no.4
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    • pp.751-763
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    • 2005
  • For a given gauge invariant state $\omega$ on the CAR algebra A isomorphic with the C$\ast$ -algebra of $2{\times}2$ complex matrices, we construct a family of quantum Markov semigroups on A which leave w invariant. By analyzing their generators, we decompose the algebra A into four eigenspaces of the semigroups and show some properties.

CONDITIONAL INDEPENDENCE AND TENSOR PRODUCTS OF CERTAIN HILBERT L(sup)$\infty$-MODULES

  • Hoover, Thomas;Lambert, Alan
    • Journal of the Korean Mathematical Society
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    • v.38 no.1
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    • pp.125-134
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    • 2001
  • Independent $\sigma$-algebras Α and Β on X, L$^2$(X, Α V Β), L$^2$(X x X, Α x Β), and the Hilbert space tensor product L$^2$(X,Α), (※Equations, See Full-text) L$^2$(X,Β), are isomorphic. In this note, we show that various Hilbert C(sup)*-algebra tensor products provide the analogous roles when independence is weakened to conditional independence.

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DYNAMICAL SYSTEMS AND GROUPOID ALGEBRAS ON HIGHER RANK GRAPHS

  • Yi, In-Hyeop
    • The Pure and Applied Mathematics
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    • v.19 no.2
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    • pp.199-209
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    • 2012
  • For a locally compact higher rank graph ${\Lambda}$, we construct a two-sided path space ${\Lambda}^{\Delta}$ with shift homeomorphism ${\sigma}$ and its corresponding path groupoid ${\Gamma}$. Then we find equivalent conditions of aperiodicity, cofinality and irreducibility of ${\Lambda}$ in (${\Lambda}^{\Delta}$, ${\sigma}$), ${\Gamma}$, and the groupoid algebra $C^*({\Gamma})$.

EXPONENTIAL STABILITY OF INFINITE DIMENSIONAL LINEAR SYSTEMS

  • Shin, Chang Eon
    • Communications of the Korean Mathematical Society
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    • v.31 no.3
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    • pp.603-611
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    • 2016
  • In this paper, we show that if $\mathcal{A}$ is a differential subalgebra of Banach algebras $\mathcal{B}({\ell}^r)$, $1{\leq}r{\leq}{\infty}$, then solutions of the infinite dimensional linear system associated with a matrix in $\mathcal{A}$ have its p-exponential stability being equivalent to each other for different $1{\leq}p{\leq}{\infty}$.