• 제목/요약/키워드: composition operators

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A NOTE ON WEIGHTED COMPOSITION OPERATORS ON MEASURABLE FUNCTION SPACES

  • Jbbarzadeh, M.R.
    • 대한수학회지
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    • 제41권1호
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    • pp.95-105
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    • 2004
  • In this paper we will consider the weighted composition operators W = $uC_{\tau}$ between $L^{p}$$(X,\sum,\mu$) spaces and Orlicz spaces $L^{\phi}$$(X,\sum,\mu$) generated by measurable and non-singular transformations $\tau$ from X into itself and measurable functions u on X. We characterize the functions u and transformations $\tau$ that induce weighted composition operators between $L^{p}$ -spaces by using some properties of conditional expectation operator, pair (u,${\gamma}$) and the measure space $(X,\sum,\mu$). Also, some other properties of these types of operators will be investigated.

WEIGHTED COMPOSITION OPERATORS ON NACHBIN SPACES WITH OPERATOR-VALUED WEIGHTS

  • Klilou, Mohammed;Oubbi, Lahbib
    • 대한수학회논문집
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    • 제33권4호
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    • pp.1125-1140
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    • 2018
  • Let A be a normed space, ${\mathcal{B}}(A)$ the algebra of all bounded operators on A, and V a family of strongly upper semicontinuous functions from a Hausdorff completely regular space X into ${\mathcal{B}}(A)$. In this paper, we investigate some properties of the weighted spaces CV (X, A) of all A-valued continuous functions f on X such that the mapping $x{\mapsto}v(x)(f(x))$ is bounded on X, for every $v{\in}V$, endowed with the topology generated by the seminorms ${\parallel}f{\parallel}v={\sup}\{{\parallel}v(x)(f(x)){\parallel},\;x{\in}X\}$. Our main purpose is to characterize continuous, bounded, and locally equicontinuous weighted composition operators between such spaces.

SOME CLASSES OF OPERATORS RELATED TO (m, n)-PARANORMAL AND (m, n)*-PARANORMAL OPERATORS

  • Shine Lal Enose;Ramya Perumal;Prasad Thankarajan
    • 대한수학회논문집
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    • 제38권4호
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    • pp.1075-1090
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    • 2023
  • In this paper, we study new classes of operators k-quasi (m, n)-paranormal operator, k-quasi (m, n)*-paranormal operator, k-quasi (m, n)-class 𝒬 operator and k-quasi (m, n)-class 𝒬* operator which are the generalization of (m, n)-paranormal and (m, n)*-paranormal operators. We give matrix characterizations for k-quasi (m, n)-paranormal and k-quasi (m, n)*-paranormal operators. Also we study some properties of k-quasi (m, n)-class 𝒬 operator and k-quasi (m, n)-class 𝒬* operators. Moreover, these classes of composition operators on L2 spaces are characterized.

HYPERCYCLICITY OF WEIGHTED COMPOSITION OPERATORS ON THE UNIT BALL OF ℂN

  • Chen, Ren-Yu;Zhou, Ze-Hua
    • 대한수학회지
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    • 제48권5호
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    • pp.969-984
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    • 2011
  • This paper discusses the hypercyclicity of weighted composition operators acting on the space of holomorphic functions on the open unit ball $B_N$ of $\mathbb{C}^N$. Several analytic properties of linear fractional self-maps of $B_N$ are given. According to these properties, a few necessary conditions for a weighted composition operator to be hypercyclic in the space of holomorphic functions are proved. Besides, the hypercyclicity of adjoint of weighted composition operators are studied in this paper.

Weakly Hyponormal Composition Operators and Embry Condition

  • Lee, Mi-Ryeong;Park, Jung-Woi
    • Kyungpook Mathematical Journal
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    • 제49권4호
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    • pp.683-689
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    • 2009
  • We investigate the gaps among classes of weakly hyponormal composition operators induced by Embry characterization for the subnormality. The relationship between subnormality and weak hyponormality will be discussed in a version of composition operator induced by a non-singular measurable transformation.