Results 1 to 10 of about 396 (26)
Exterior products of operators and superoptimal analytic approximation
Transactions of the London Mathematical Society, 2021 We give a new algorithm for the construction of the unique superoptimal analytic approximant of a given continuous matrix‐valued function on the unit circle, using exterior powers of operators in preference to spectral or Wiener–Masani factorizations.
Dimitrios Chiotis +2 more
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Generalized Crofoot transform and applications
Concrete Operators, 2023 Matrix-valued asymmetric truncated Toeplitz operators are compressions of multiplication operators acting between two model spaces. These are the generalization of matrix-valued truncated Toeplitz operators. In this article, we describe symbols of matrix-
Khan Rewayat, Farooq Aamir
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Mean Lipschitz spaces and a generalized Hilbert operator [PDF]
, 2017 If $\mu $ is a positive Borel measure on the interval $[0, 1)$ we let $\mathcal H_\mu $ be the Hankel matrix $\mathcal H_\mu =(\mu _{n, k})_{n,k\ge 0}$ with entries $\mu _{n, k}=\mu _{n+k}$, where, for $n\,=\,0, 1, 2, \dots $, $\mu_n$ denotes the moment ...
Merchán, Noel
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Functions of self‐adjoint operators in ideals of compact operators
Journal of the London Mathematical Society, Volume 95, Issue 1, Page 157-176, February 2017., 2017 Abstract For self‐adjoint operators A,B, a bounded operator J, and a function f:R→C, we obtain bounds in quasi‐normed ideals of compact operators for the difference f(A)J−Jf(B) in terms of the operator AJ−JB. The focus is on functions f that are smooth everywhere except for finitely many points. A typical example is the function f(t)=|t|γ with γ∈(0,1).
Alexander V. Sobolev
wiley +1 more source
A hyperbolic universal operator commuting with a compact operator [PDF]
, 2019 A Hilbert space operator is called universal (in the sense of Rota) if every operator on the Hilbert space is similar to a multiple of the restriction of the universal operator to one of its invariant subspaces.
Cowen, Carl C. +1 more
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Volterra composition operators from generalized weighted weighted Bergman spaces to µ‐Bloch spaces
Journal of Function Spaces, Volume 7, Issue 3, Page 225-240, 2009., 2009 Let φ be a holomorphic self‐map and g be a fixed holomorphic function on the unit ball B. The boundedness and compactness of the operator Tg,φf(z)=∫01f(φ(tz))ℜg(tz)dtt from the generalized weighted Bergman space into the µ‐Bloch space are studied in this paper.
Xiangling Zhu
wiley +1 more source
On the weak limit of compact operators on the reproducing kernel Hilbert space and related questions
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2016 By applying the so-called Berezin symbols method we prove a Gohberg- Krein type theorem on the weak limit of compact operators on the non- standard reproducing kernel Hilbert space which essentially improves the similar results of Karaev [5]: We also in ...
Saltan Suna
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Finite‐rank intermediate Hankel operators on the Bergman space
International Journal of Mathematics and Mathematical Sciences, Volume 25, Issue 1, Page 19-31, 2001., 2001 Let L2 = L2(D, r dr dθ/π) be the Lebesgue space on the open unit disc and let La2=L2∩ℋol(D) be the Bergman space. Let P be the orthogonal projection of L2 onto La2 and let Q be the orthogonal projection onto L¯a,02={g∈L2;g¯∈La2, g(0)=0}. Then I − P ≥ Q.
Takahiko Nakazi, Tomoko Osawa
wiley +1 more source
The Weiss conjecture on admissibility of observation operators for contraction semigroups [PDF]
, 2001 We prove the conjecture of George Weiss for contraction semigroups on Hilbert spaces, giving a characterization of infinite-time admissible observation functionals for a contraction semigroup, namely that such a functional C is infinite-time admissible ...
A. Simard +13 more
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A Hankel matrix acting on spaces of analytic functions [PDF]
, 2017 If $\mu $ is a positive Borel measure on the interval $[0, 1)$ we let $\mathcal H_\mu $ be the Hankel matrix $\mathcal H_\mu =(\mu _{n, k})_{n,k\ge 0}$ with entries $\mu _{n, k}=\mu _{n+k}$, where, for $n\,=\,0, 1, 2, \dots $, $\mu_n$ denotes the moment ...
Girela, Daniel, Merchán, Noel
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