Results 1 to 10 of about 1,178 (152)
On boundedness of integral means of Blaschke product logarithms
Mathematical Modelling and Analysis, 2003 Using the Fourier series method for the analytic functions, we obtain a result characterizing the behaviour of the integral means of Blaschke product logarithms.
YA. V. Vasylkiv +2 more
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H∞ interpolation constrained by Beurling–Sobolev norms
Moroccan Journal of Pure and Applied Analysis, 2023 We consider a Nevanlinna–Pick interpolation problem on finite sequences of the unit disc, constrained by Beurling–Sobolev norms. We find sharp asymptotics of the corresponding interpolation quantities, thereby improving the known estimates. On our way we
Baranov Anton, Zarouf Rachid
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Characterizations of rectangular (para)-unitary rational functions [PDF]
Opuscula Mathematica, 2016 We here present three characterizations of not necessarily causal, rational functions which are (co)-isometric on the unit circle: (i) through the realization matrix of Schur stable systems, (ii) the Blaschke-Potapov product, which is then employed to ...
Daniel Alpay +2 more
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Cyclicity in de Branges–Rovnyak spaces
Moroccan Journal of Pure and Applied Analysis, 2023 In this paper, we study the cyclicity problem with respect to the forward shift operator Sb acting on the de Branges–Rovnyak space ℋ (b) associated to a function b in the closed unit ball of H∞ and satisfying log(1− |b| ∈ L1(𝕋).
Fricain Emmanuel, Grivaux Sophie
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Endomorphisms of the Toeplitz algebra
Учёные записки Казанского университета: Серия Физико-математические науки, 2023 This article describes all injective endomorphisms of the classical Toeplitz algebra. Their connection with endomorphisms of the algebra of continuous functions on the unit circle and with coverings over the unit circle was considered.
S. A. Grigoryan, A. Yu. Kuznetsova
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Analytic in the unit polydisc functions of bounded L-index in direction
Математичні Студії, 2023 The concept of bounded $L$-index in a direction $\mathbf{b}=(b_1,\ldots,b_n)\in\mathbb{C}^n\setminus\{\mathbf{0}\}$ is generalized for a class of analytic functions in the unit polydisc, where $L$ is some continuous function such that for every $z=(z_1 ...
A. Bandura, T. Salo
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SYSTEM COMPLETENESS OF RESONANCE STATES FOR GRAPHS WITH DIFFERENT GEOMETRY [PDF]
Научно-технический вестник информационных технологий, механики и оптики, 2019 Resonant states (quasi-intrinsic functions) play an important role in the scattering problem and in the description of transportprocesses. We consider the system completeness of resonance states on a finite subgraph for quantum graphs with both finite ...
I. V. Blinova +2 more
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Finite sections of truncated Toeplitz operators
Concrete Operators, 2014 We describe the C*-algebra associated with the finite sections discretization of truncated Toeplitz operators on the model space K2u where u is an infinite Blaschke product.
Roch Steffen
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Advances in Difference Equations, 2021 This paper deals with boundary value problems for local and nonlocal Laplace operator in 2D with exponential nonlinearities, the so-called Liouville type equations.
Angela Slavova, Petar Popivanov
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Maximal subalgebra of Douglas algebra
International Journal of Mathematics and Mathematical Sciences, 1988 When q is an interpolating Blaschke product, we find necessary and sufficient conditions for a subalgebra B of H∞[q¯] to be a maximal subalgebra in terms of the nonanalytic points of the noninvertible interpolating Blaschke products in B. If the set M(B)⋂
Carroll J. Gullory
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