List of Articles composition operator

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  1 - Essential norm estimates of generalized weighted composition operators into weighted type spaces
  A. H. Sanatpour M. Hassanlou
  Weighted composition operators appear in the study of dynamical systems and also in characterizing isometries of some classes of Banach spaces. One of the most important generalizations of weighted composition operators, are generalized weighted composition operators wh More

  Weighted composition operators appear in the study of dynamical systems and also in characterizing isometries of some classes of Banach spaces. One of the most important generalizations of weighted composition operators, are generalized weighted composition operators which in special cases of their inducing functions give different types of well-known operators like: weighted composition operators, composition operators, multiplication operators and composition operators followed by differentiation operators. In this paper we study generalized weighted composition operators and give estimates for the essential norm of such operators on certain Banach spaces of analytic functions into weighted type spaces. The underlying Banach spaces of analytic functions include Bloch spaces, Zygmund spaces and weighted type spaces. Our estimates for the essential norms of generalized weighted composition operators imply necessary and sufficient conditions for the compactness of such operators. As another application of our results, we obtain essential norm estimates of certain well-known operators which are special cases of generalized weighted composition operators. Manuscript profile
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  2 - Some properties of sums of weighted composition operators on the Fock space
  Mahsa Fatehi Asma Negahdari
  Let H be a Hilbert space. For each f∈H, we define a multiplication operator M_φ by M_φ (f)=φf. Let φ be an entire function. For each f belongs to the Fock space F^2, the composition operator C_φ is defined by C_φ (f)=f∘φ. For entire func More

  Let H be a Hilbert space. For each f∈H, we define a multiplication operator M_φ by M_φ (f)=φf. Let φ be an entire function. For each f belongs to the Fock space F^2, the composition operator C_φ is defined by C_φ (f)=f∘φ. For entire functions ψ, φ and f∈F^2, the weighted composition operator C_(ψ,φ) on F^2 are given by C_(ψ,φ) (f)=ψ.(f∘φ). Let T be a bounded operator on H, the set W(T)={⟨Tf,f⟩:‖f‖=1} is called the numerical range of T. In this paper, we find the point spectrum of some operators C_(ψ_1,φ_1 )+C_(ψ_2,φ_2 ), when φ_1 and φ_2 have the some fixed point. Moreover, we obtain an invariant subspace for the operator (C_(ψ_1,φ_1 )+C_(ψ_2,φ_2 ) )^*. Then by these results, for compact operators C_(ψ_1,φ_1 ) and C_(ψ_2,φ_2 ), we find the spectrum of C_(ψ_1,φ_1 )+C_(ψ_2,φ_2 ). Then for φ_1 and φ_2 which have the some fixed point, we investigate the numerical range of C_(ψ_1,φ_1 )+C_(ψ_2,φ_2 ). Manuscript profile
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  3 - Mean Ergodic Weighted Composition Operator 𝝀𝑪𝝋 on Bloch Space
  Fakhreddin falahat Zahra Kamali
  Investigating the mean ergodicity of composition operators on various Banach Spaces has always been of interest to mathematicians and many authors studied this topics intensively, in many different spaces, such as, the space of all holomorphic functions on unit disk, Ha More

  Investigating the mean ergodicity of composition operators on various Banach Spaces has always been of interest to mathematicians and many authors studied this topics intensively, in many different spaces, such as, the space of all holomorphic functions on unit disk, Hardy space and Bloch space. In this paper, for a self map of the unit disk, φ and λ∈ℂ, we consider weighted composition operator, (λ𝐶φ)𝑓=λ𝑓𝑜φ , for every 𝑓 in Bloch space and Little Bloch space and inquiry the conditions under which the weighted composition operator 𝜆𝐶𝜑, is mean ergodic or uniformly mean ergodic on the Bloch and Little Bloch Space. In fact, we will show, if |λ|>1,𝜆𝐶𝜑, cannot be power bounded, mean ergodic or uniformly mean ergodic, in contrast, if |λ|<1, 𝜆𝐶𝜑, is always power bounded, mean ergodic or uniformly mean ergodic. In the case, |λ|=1, we will see that it depends directly to the Denjoy-Wolff point of 𝜑. Manuscript profile
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  4 - Spectrum and essential spectrum of linear combinations of composition operators on the Hardy space H2
  M. Haji Shaabani M. Fatehi M. Farzi Haromi
  Let -----. For an analytic self-map --- of --- , Let --- be the composition operator with composite map --- so that ----. Let --- be a bounded analytic function on --- . The weighted composition operator --- is defined by --- . Suppose that --- is the Hardy space, consi More

  Let -----. For an analytic self-map --- of --- , Let --- be the composition operator with composite map --- so that ----. Let --- be a bounded analytic function on --- . The weighted composition operator --- is defined by --- . Suppose that --- is the Hardy space, consisting of all analytic functions defined on --- , whose Maclaurin cofficients are square summable. ..... Manuscript profile
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  5 - عملگرهای ترکیبی مشتق پذیر وزن دار از فضاهای برگمن وزن دار با وزن های پذیرفتنی به فضاهای از نوع بلاخ
  شایسته رضایی
  فرض کنید خودنگاشتی تحلیلی روی قرص واحد  در صفحه مختلط ،  یک عدد صحیح نامنفی و  تابعی تحلیلی روی  باشد. در این صورت برای تابع تحلیلی  روی  عملگر ترکیبی مشتق پذیر وزن دار به صورت تعریف می شود که . در این مقاله، کرانداری و فشردگی  از فضاه More

  فرض کنید خودنگاشتی تحلیلی روی قرص واحد  در صفحه مختلط ،  یک عدد صحیح نامنفی و  تابعی تحلیلی روی  باشد. در این صورت برای تابع تحلیلی  روی  عملگر ترکیبی مشتق پذیر وزن دار به صورت تعریف می شود که . در این مقاله، کرانداری و فشردگی  از فضاهای برگمن وزن دار با وزن های پذیرفتنی به فضاهای از نوع بلاخ را بررسی می کنیم. Manuscript profile
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  6 - Essential Norm of Composition Operator as a Mapping on Weighted Bergman Space with Regular Weight
  Shayesteh Rezaei
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  7 - Generalized composition operators from logarithmic Bloch type spaces to Q_K type spaces
  Sh. Rezaei H. Mahyar
  In this paper boundedness and compactness of generalized composition oper-ators from logarithmic Bloch type spaces to Q_K type spaces are investigated.

  In this paper boundedness and compactness of generalized composition oper-ators from logarithmic Bloch type spaces to Q_K type spaces are investigated. Manuscript profile
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  8 - Some properties of Moore$-$Penrose inverse of weighted composition operators
  M. Sohrabi
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  9 - Compact composition operators on real Banach spaces of complex-valued bounded Lipschitz functions
  D. Alimohammadi S. Sefidgar
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  10 - Some algebraic properties of Lambert Multipliers on $L^2$ spaces
  A. Zohri S. Khalil Sarbaz
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