Results 1 to 10 of about 109 (35)
Some new results on the weaving of K-g-frames in Hilbert spaces
Open Mathematics, 2021 In this paper, we provide some conditions for a K-woven pair of K-g-frames to be preserved under an operator and particularly, we report that applying two different operators to a K-woven pair of K-g-frames can leave them K-woven.
Xiang Zhong-Qi
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Open Mathematics, 2020 Given the abstract evolution equation y′(t)=Ay(t),t∈ℝ,y^{\prime} (t)=Ay(t),t\in {\mathbb{R}}, with a scalar type spectral operator A in a complex Banach space, we find conditions on A, formulated exclusively in terms of the location of its spectrum in ...
Markin Marat V.
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Compact well-bounded operators [PDF]
, 2001 Every compact well-bounded operator has a representation as a linear combination of disjoint projections reminiscent of the representation of compact self-adjoint operators. In this note we show that the converse of this result holds, thus characterizing
Doust, I., Qingping, C.
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Asymptotic limits of operators similar to normal operators [PDF]
, 2014 Sz.-Nagy's famous theorem states that a bounded operator $T$ which acts on a complex Hilbert space $\mathcal{H}$ is similar to a unitary operator if and only if $T$ is invertible and both $T$ and $T^{-1}$ are power bounded.
Gehér, György
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Why the Riesz transforms are averages of the dyadic shifts? [PDF]
, 2002 The first author showed in [18] that the Hilbert transform lies in the closed convex hull of dyadic singular operators -so-called dyadic shifts. We show here that the same is true in any $\mathbb{R}^n$ -the Riesz transforms can be obtained as the results
Petermichl, S., Treil, S., Volberg, A.
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Local spectral theory of endomorphisms of the disk algebra
Demonstratio Mathematica, 2016 Let A(𝔻) denote the disk algebra. Every endomorphism of A(𝔻) is induced by some ϕ ∈ A(𝔻) with ‖ϕ‖ ≤ 1. In this paper, it is shown that if ϕ is not an automorphism of 𝔻 and ϕ has a fixed point in the open unit disk then the endomorphism induced by ϕ is ...
Trivedi Shailesh, Chandra Harish
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Isomorphisms of $AC(\sigma)$ spaces for linear graphs
, 2020 We show that among compact subsets of the plane which are drawings of linear graphs, two sets $\sigma$ and $\tau$ are homeomorphic if and only if the corresponding spaces of absolutely continuous functions (in the sense of Ashton and Doust) are ...
Al-shakarchi, Shaymaa, Doust, Ian
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Open Mathematics, 2019 It is shown that, if all weak solutions of the evolution ...
Markin Marat V.
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On the similarity of Sturm-Liouville operators with non-Hermitian boundary conditions to self-adjoint and normal operators [PDF]
, 2011 We consider one-dimensional Schroedinger-type operators in a bounded interval with non-self-adjoint Robin-type boundary conditions. It is well known that such operators are generically conjugate to normal operators via a similarity transformation ...
A Mostafazadeh +40 more
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