Search Results - "Tsekanovskii, Eduard"

On von Neumann's problem in extension theory of nonnegative operators by ARLINSKII, Yury, TSEKANOVSKII, Eduard

“…The solution of von Neumann's problem about parametrization of all nonegative selfadjoint extensions of a nonnegative densely defined operator in terms of his…”
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Accretive and Sectorial Extensions of Nonnegative Symmetric Operators by Arlinskiĭ, Yury, Kovalev, Yury, Tsekanovskiĭ, Eduard

“…We present the solution to the Phillips–Kato restricted extension problem about description and parametrization of the domains of all maximal accretive and…”
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Non-self-adjoint Jacobi matrices with a rank-one imaginary part by Arlinskiĭ, Yury, Tsekanovskiĭ, Eduard

“…We develop direct and inverse spectral analysis for finite and semi-infinite non-self-adjoint Jacobi matrices with a rank-one imaginary part. It is shown that…”
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Contractions with rank one defect operators and truncated CMV matrices by Arlinskiĭ, Yury, Golinskiĭ, Leonid, Tsekanovskiĭ, Eduard

“…The main issue we address in the present paper are the new models for completely nonunitary contractions with rank one defect operators acting on some Hilbert…”
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A general realization theorem for matrix-valued Herglotz–Nevanlinna functions by Belyi, Sergey, Hassi, Seppo, de Snoo, Henk, Tsekanovskiiˇ, Eduard

“…New special types of stationary conservative impedance and scattering systems, the so-called non-canonical systems, involving triplets of Hilbert spaces and…”
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Realization of inverse Stieltjes functions $(-m_\alpha(z))$ by Schrodinger L-systems by Belyi, Sergey, Tsekanovskii, Eduard

“…We study L-system realizations of the original Weyl-Titchmarsh functions $(-m_\alpha(z))$. In the case when the minimal symmetric Schr\"odinger operator is…”
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On Matrix-Valued Herglotz Functions by Gesztesy, Fritz, Tsekanovskii, Eduard

“…We provide a comprehensive analysis of matrix–valued Herglotz functions and illustrate their applications in the spectral theory of self–adjoint Hamiltonian…”
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The original Weyl-Titchmarsh functions and sectorial Shr\"odinger L-systems by Belyi, Sergey, Tsekanovskii, Eduard

“…Contributions to Mathematics and Statistics, Acta Wasaensia, vol. 462, (2021), pp. 37-54 In this paper we study the L-system realizations generated by the…”
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On realization of the original Weyl-Titchmarsh functions by Shr\"odinger L-systems by Belyi, Sergey, Tsekanovskii, Eduard

“…Complex Analysis and Operator Theory, vol. 15 (1), 11 (2021) We study realizations generated by the original Weyl-Titchmarsh functions $m_\infty(z)$ and…”
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The L-system representation and c-entropy by Belyi, Sergey, Makarov, Konstantin A, Tsekanovskii, Eduard

“…Given a symmetric operator $\dot A$ with deficiency indices $(1,1)$ and its self-adjoint extension $A$ in a Hilbert space $\mathcal{H}$, we construct a…”
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Perturbations of Donoghue classes and inverse problems for L-systems by Belyi, Sergey, Tsekanovskii, Eduard

“…We study linear perturbations of Donoghue classes of scalar Herglotz-Nevanlinna functions by a real parameter $Q$ and their representations as impedance of…”
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On the c-entropy of L-systems with Schrodinger operator by Belyi, Sergey, Makarov, Konstantin, Tsekanovskii, Eduard

“…Complex Analysis and Operator Theory, vol. 16, 107 (2022) We study L-systems whose main operators are extensions of one-dimensional half-line Schr\"odinger…”
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The von Neumann Problem for Nonnegative Symmetric Operators by Arlinskii, Yury, Tsekanovskii, Eduard

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On realization of the Kreĭn-Langer class Nκ of matrix-valued functions in Pontryagin spaces by Arlinskiĭ, Yury, Belyi, Sergey, Derkach, Vladimir, Tsekanovskii, Eduard

“…In this paper the realization problems for the Kreĭn–Langer class Nκ of matrix‐valued functions are being considered. We found the criterion when a given…”
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On Krein's formula in indefinite metric spaces by Belyi, Sergey, Tsekanovskii, Eduard

“…In this paper we extend some of the recent results in connection with the Krein resolvent formula which provides a complete description of all canonical…”
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On unimodular transformations of conservative L-systems by Belyi, Sergey, Makarov, Konstantin, Tsekanovskii, Eduard

“…We study unimodular transformations of conservative $L$-systems. Classes $\sM^Q$, $\sM^Q_\kappa$, $\sM^{-1,Q}_\kappa$ that are impedance functions of the…”
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On the Weyl-Titchmarsh and Liv\v{s}ic functions by Makarov, Konstantin, Tsekanovskii, Eduard

“…We establish a mutual relationship between main analytic objects for the dissipative extension theory of a symmetric operator $\dot A$ with deficiency indices…”
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An Addendum to Krein's Formula by Gesztesy, Fritz, Makarov, Konstantin A, Tsekanovskii, Eduard

“…We provide additional results in connection with Krein's formula, which describes the resolvent difference of two self-adjoint extensionsA1andA2of a densely…”
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A system coupling and Donoghue classes of Herglotz-Nevanlinna functions by Belyi, Sergey, Makarov, Konstantin, Tsekanovskii, Eduard

“…We study the impedance functions of conservative L-systems with the unbounded main operators. In addition to the generalized Donoghue class $\sM_\kappa$ of…”
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On Krein's Formula in the Case of Non-densely Defined Symmetric Operators by Belyi, Sergey, Menon, Govind, Tsekanovskii, Eduard

“…In this paper we provide some additional results related to Krein's resolvent formula for a non-densely defined symmetric operator. We show that coefficients…”
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