3 research outputs found

    Laplace--Carleson embeddings on model spaces and boundedness of truncated Hankel and Toeplitz operators

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    A characterisation is given of bounded embeddings from weighted L2L^2 spaces on bounded intervals into L2L^2 spaces on the half-plane, induced by isomorphisms given by the Laplace transform onto weighted Hardy and Bergman spaces (Zen spaces). As an application necessary and sufficient conditions are given for the boundedness of truncated Hankel and Toeplitz integral operators, including the weighted case.Comment: 19 pages. Some minor revision

    Admissibility of retarded diagonal systems with one-dimensional input space

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    We investigate infinite-time admissibility of a control operator BB in a Hilbert space state-delayed dynamical system setting of the form zΛ™(t)=Az(t)+A1z(tβˆ’Ο„)+Bu(t)\dot{z}(t)=Az(t)+A_1 z(t-\tau)+Bu(t), where AA generates a diagonal C0C_0-semigroup, A1∈L(X)A_1\in\mathcal{L}(X) is also diagonal and u∈L2(0,∞;C)u\in L^2(0,\infty;\mathbb{C}). Our approach is based on the Laplace embedding between L2L^2 and the Hardy space H2(C+)H^2(\mathbb{C}_+). The results are expressed in terms of the eigenvalues of AA and A1A_1 and the sequence representing the control operator.Comment: 25 pages, 2 figure
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