Results 11 to 20 of about 42 (42)
Hyponormal Toeplitz Operators on the Dirichlet Spaces
Abstract and Applied Analysis, Volume 2013, Issue 1, 2013., 2013 We completely characterize the hyponormality of bounded Toeplitz operators with Sobolev symbols on the Dirichlet space and the harmonic Dirichlet space.
Puyu Cui +2 more
wiley +1 more source
The Near Subnormal Weighted Shift and Recursiveness
International Journal of Analysis, Volume 2013, Issue 1, 2013., 2013 We aim at studying the near subnormality of the unilateral weighted shifts, whose moment sequences are defined by linear recursive relations of finite order. Using the basic properties of recursive sequences, we provide a natural necessary condition, that ensure the near subnormality of this important class of weighted shifs.
R. Ben Taher, M. Rachidi, Chuanxi Qian
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Quality and Reliability Engineering International, Volume 40, Issue 1, Page 202-219, February 2024.Abstract Laser welding is particularly relevant in the industry thanks to its simplicity, flexibility and final quality. The industry 4.0 and sustainable manufacturing framework gives massive attention to in situ and non‐destructive inspection methods to predict laser weld final quality.
Giacomo Maculotti +2 more
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More on (α, β)‐Normal Operators in Hilbert Spaces
Abstract and Applied Analysis, Volume 2012, Issue 1, 2012., 2012 We study some properties of (α, β)‐normal operators and we present various inequalities between the operator norm and the numerical radius of (α, β)‐normal operators on Banach algebra ℬ(ℋ) of all bounded linear operators T : ℋ → ℋ, where ℋ is Hilbert space.
Rasoul Eskandari +3 more
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Similarity of C1: Operators and the Hyperinvariant Subspace Problem
Journal of Mathematics, Volume 2024, Issue 1, 2024.In the present paper, we first show that the existence of the solutions of the operator equation S∗XT = X is related to the similarity of operators of class C1., and then we give a sufficient condition for the existence of nontrivial hyperinvariant subspaces. These subspaces are the closure of ranφ(T) for some singular inner functions φ.
Abdelkader Segres +3 more
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A Note on Unbounded Hyponormal Composition Operators in L2‐Spaces
Journal of Function Spaces, Volume 2012, Issue 1, 2012., 2012 We construct an unbounded hyponormal composition operator Cϕ in L2‐space such that the domains of Cϕ2 and Cϕ2 are trivial.
Piotr Budzyński, Anna Kamińska
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Toeplitz Operators on the Dirichlet Space of 𝔹n
Abstract and Applied Analysis, Volume 2012, Issue 1, 2012., 2012 We study the algebraic properties of Toeplitz operators on the Dirichlet space of the unit ball 𝔹n. We characterize pluriharmonic symbol for which the corresponding Toeplitz operator is normal or isometric. We also obtain descriptions of conjugate holomorphic symbols of commuting Toeplitz operators.
HongZhao Lin +2 more
wiley +1 more source
International Journal of Mathematics and Mathematical Sciences, Volume 2012, Issue 1, 2012., 2012 We prove some further properties of the operator T ∈ [nQN] (n‐power quasinormal, defined in Sid Ahmed, 2011). In particular we show that the operator T ∈ [nQN] satisfying the translation invariant property is normal and that the operator T ∈ [nQN] is not supercyclic provided that it is not invertible. Also, we study some cases in which an operator T ∈ [
Sid Ahmed Ould Ahmed Mahmoud +1 more
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Nonlinear Analysis: Algorithm, Convergence, and Applications 2014
, 2014 Abstract and Applied Analysis, Volume 2014, Issue 1, 2014.
Yisheng Song +4 more
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An invariant for certain operator algebras. [PDF]
Proc Natl Acad Sci U S A, 1974 Carey RW, Pincus JD.
europepmc +1 more source