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Your search keyword '"Ismailov, Zameddin I."' showing total 41 results
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41 results on '"Ismailov, Zameddin I."'

1. Generalizations of the Numerical Radius, Crawford Number and Numerical Index Functions in the Weighted Case

Author

Ismailov, Zameddin I. and Al, Pembe Ipek

Subjects
Mathematics - Functional Analysis, Mathematics - Spectral Theory
Abstract

In this article, firstly, some simple and smoothness properties of the weighted numerical radius and the weighted Crawford number functions are investigated. Then, some generalization formulas for lower and upper bounds of the weighted numerical radius function are obtained. Later on, some evaluations for lower and upper bounds of the weighted numerical index are given. The obtained results are generalized some well-known famous results about the special weighted numerical radius and the special weighted Crawford number functions in the recently literature. Also, the different and useful results are provided to the literature.

Published
2024

9. SPECTRA AND PSEUDOSPECTRA OF THE DIRECT SUM OPERATORS

Author

ISMAILOV, Zameddin I. and IPEK AL, Pembe

Subjects
Direct sum of operators,spectrum,pseudospectrum,spectral radii, Engineering, Mühendislik
Abstract

In this paper, the relationships between spectrum and pseudospectrum of the direct sum of linear operators in the direct sum of Hilbert spaces and its coordinate operators have been researched. Also, the analogous relations of some numerical characteristics (spectral and pseudospectral radii) of such operators have been investigated.

Published
2020

10. Characteristic Numbers of Upper Triangular One-Band Block Operator Matrices

Author

Mert, Rukiye Öztürk, Al, Pembe İpek, Ismailov, Zameddin I., and [Belirlenecek]

Subjects
Mathematics::Operator Algebras, [No Keywords]
Abstract

In this work the boundedness and compactness properties of upper triangular one-band block operator matrices in the infinite direct sum of Hilbert spaces have been studied. We also obtain the necessary and sufficient conditions when these operators belong to Schatten-von Neumann classes.

Published
2018

11. Discreteness of Spectrum of Normal Differential Operators for First Order

Author

Mert, Rukiye Öztürk, Al, Pembe İpek, Yılmaz, Bülent, Ismailov, Zameddin I., and [Belirlenecek]

Subjects
[No Keywords]
Abstract

In this work under the condition A?1 ? C?(H), we investigate the discreteness of spectrum of normal extensions in detail. Later on, the asymptotical behavior of eigenvalues of any normal extension has been examined.

Published
2018

14. Dissipative canonical type differential operators for first order.

Author

ÖZTÜRK MERT, Rukiye, ISMAILOV, Zameddin I., and İPEK AL, Pembe

Subjects
*VECTOR spaces, *FUNCTION spaces, *HILBERT space, *LINEAR orderings, *VECTOR valued functions, *DIFFERENTIAL operators
Abstract

In this paper, using the Calkin-Gorbachuk method, the general form of all maximally dissipative extensions of the minimal operator generated by the first order linear symmetric canonical type quasi-differential expression in the weighted Hilbert space of vector functions has been found. Also, the spectrum set of these extensions has been investigated. [ABSTRACT FROM AUTHOR]

Published
2020
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17. Selfadjoint extensions of a singular multipoint differential operator of first order

Author

Ismailov, Zameddin I., Öztürk Mert, Rukiye, and Hitit Üniversitesi, Fen Edebiyat Fakültesi, Matematik Bölümü

Subjects
Quantum field theory, Mathematics::Functional Analysis, selfadjoint extension, lcsh:Mathematics, Mathematics::Spectral Theory, multipoint differential operators, lcsh:QA1-939, spectrum
Abstract

In this work, we describe all selfadjoint extensions of the minimal operator generated by linear singular multipoint symmetric differential expression $l=(l_1,l_2,l_3)$, $l_k=ifrac{d}{dt}+A_k$ with selfadjoint operator coefficients $A_k$, $k=1,2,3$ in a Hilbert space. This is done as a direct sum of Hilbert spaces of vector-functions $$ L_2(H,(-infty ,a_1))oplus L_2(H,(a_2,b_2)) oplus L_2(H,(a_3,+infty)) $$ where $-infty

Published
2013

18. SCHATTEN-VON NEUMANN CHARACTERISTIC OF INFINITE TRIDIAGONAL BLOCK OPERATOR MATRICES.

Author

AL, PEMBE IPEK and ISMAILOV, ZAMEDDIN I.

Subjects
*HILBERT space, *MATRICES (Mathematics), *COMPACT operators, *COMPOSITION operators, *VON Neumann algebras
Abstract

In this paper, the boundedness and compactness properties of infinite tridiagonal block operator matrices in the direct sum of Hilbert spaces are studied. The necessary and sufficient conditions for these operators belong to Schatten-von Neumann class are given. Then, the results are supported by applications. [ABSTRACT FROM AUTHOR]

Published
2019
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19. Maximal sectorial differential operators for first order

Author

Ismailov, Zameddin I., Öztürk Mert, Rukiye, and Hitit Üniversitesi, Fen Edebiyat Fakültesi, Matematik Bölümü

Subjects
Separable Hilbert Space, Self-Adjoint, M-Accretive And M-Sectorial Operators, Extension, M-Accumulative, Linear Relation, Mathematics::Spectral Theory, Aspectrum, M-Dissipative
Abstract

research In this study, the maximal sectorial linear relations are described. Then, the discreteness of the spectrum of the linear maximal sectorial operators and asymptotical behavior of the eigenvalues of such operators in terms of the eigenvalues of its real part are investigated. Moreover, one result for the differential operators for first order in the Hilbert space of vector functions in finite interval is obtained.

Published
2015

21. Normal extensions of a singular differential operator on the right semi-axis

Author

Ismailov, Zameddin I., Öztürk Mert, Rukiye, and Hitit Üniversitesi, Fen Edebiyat Fakültesi, Matematik Bölümü

Subjects
Spectrum, Singular Differential Operators, Everitt-Zettl and Calkin-Gorbachuk Methods, Normal Extension
Abstract

In this work, based on the method of Everitt-Zettl and using the Calkin-Gorbachuk method, all normal extensions of the minimal operator generated by a linear singular formally normal differential-operator expression of the first order in Hilbert spaces of vector-functions on the right semi-axis in terms of boundary values are described. Furthermore, the structure of the spectrum of these extensions is investigated. © The Eurasian National University.

Published
2014

25. SELFADJOINT SINGULAR DIFFERENTIAL OPERATORS FOR FIRST ORDER.

Author

IPEK, PEMBE and ISMAILOV, ZAMEDDIN I.

Subjects
*SELFADJOINT operators, *LINEAR operators, *FIRST-order logic, *PARAMETERIZATION, *DIFFERENTIAL operators
Abstract

The parametrization of all selfadjoint extensions of the minimal operator generated by first order linear symmetric singular differential-operator expression in the Hilbert space of vector-functions denned at the right semi-axis has been given. To this end we use the Calkin-Gorbachuk method. Finally, the structure of spectrum set of such extensions is researched. [ABSTRACT FROM AUTHOR]

Published
2017
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30. BOUNDED SOLVABILITY OF MIXED-TYPE FUNCTIONAL DIFFERENTIAL OPERATORS FOR FIRST ORDER.

Author

YILMAZ, BÜLENT and ISMAILOV, ZAMEDDIN I.

Subjects
*MATHEMATICAL bounds, *FUNCTIONAL differential equations, *OPERATOR theory, *GROUP extensions (Mathematics), *HILBERT space
Abstract

In this article, we study all boundedly solvable extensions generated by linear mixed-type (forward-backward) functional differential-operator expressions of first order in the Hilbert space of vector-functions on a finite interval. Our main tools are methods of operator theory. Also we study the structure of the spectrum of these extensions. [ABSTRACT FROM AUTHOR]

Published
2016

31. Structure of spectrum of solvable pantograph differential operators for the first order.

Author

Ismailov, Zameddin I., Çevik, Elif O., Guler, Bahadir O., and Ipek, Pembe

Subjects
*DIFFERENTIAL operators, *RESOLVENTS (Mathematics), *VECTOR fields, *MATHEMATICAL functions, *HILBERT space
Abstract

In this work, based on M. I. Visik's result all solvable extensions of the minimal operator generated by the linear pantograph-type delay differential-operator expression for the first order in the Hilbert space of vector-functions at finite interval in terms of boundary values are described. Later on, the structure of spectrum of these extensions is investigated. [ABSTRACT FROM AUTHOR]

Published
2014
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32. Self-adjoint extensions of singular third-order differential operator and applications.

Author

Bairamov, Elgiz, Sertbaş, Meltem, and Ismailov, Zameddin I.

Subjects
ADJOINT operators (Quantum mechanics), MATHEMATICAL singularities, DIFFERENTIAL operators, MATHEMATICAL symmetry, LINEAR differential equations
Abstract

In this work, a self-adjoint extensions of the minimal operator generated by symmetric linear differential expressions for third order with self-adjoint operator coefficients in the Hilbert space of Hilbert space valued functions defined in right and separated left-right semi-axes in terms of boundary values are investigated. The obtained results are supplied by the applications in both cases. [ABSTRACT FROM AUTHOR]

Published
2014
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35. SELFADJOINT SINGULAR DIFFERENTIAL OPERATORS OF FIRST ORDER AND THEIR SPECTRUM.

Author

ISMAILOV, ZAMEDDIN I. and IPEK, PEMBE

Subjects
*DIFFERENTIAL equations, *HILBERT space, *QUANTUM thermodynamics, *UNITARY operators, *QUANTUM Zeno dynamics
Abstract

Based on Calkin-Gorbachuk method, we describe all selfadjoint extensions of the minimal operator generated by linear multipoint singular symmetric differential-operator, as a direct sum of weighted Hilbert space of vector-functions. Another approach to the investigation of this problem has been done by Everitt, Zettl and Markus. Also we study the structure of spectrum of these extensions. [ABSTRACT FROM AUTHOR]

Published
2016

36. SOLVABILITY OF MULTIPOINT DIFFERENTIAL OPERATORS OF FIRST ORDER.

Author

ISMAILOV, ZAMEDDIN I. and IPEK, PEMBE

Subjects
*OPERATOR theory, *HILBERT space, *QUANTUM thermodynamics, *EIGENFUNCTION expansions, *FACTORIZATION of operators
Abstract

Based on methods of operator theory, we describe all boundedly solvable extensions of the minimal operator generated by a linear multipoint functional differential-operator expression of first order, in a direct sum of Hilbert space of vector-functions. We also study the structure of spectrum of these extensions. [ABSTRACT FROM AUTHOR]

Published
2015

37. NORMAL EXTENSIONS OF A SINGULAR MULTIPOINT DIFFERENTIAL OPERATOR OF FIRST ORDER.

Author

ISMAILOV, ZAMEDDIN I. and MERT, RUKIYEÖZTÜRK

Subjects
*OPERATOR theory, *DIFFERENTIAL equations, *SELFADJOINT operators, *HILBERT space, *COEFFICIENTS (Statistics)
Abstract

In this work, we describe all normal extensions of the minimal operator generated by linear singular multipoint formally normal differential expression l = (l1, l2, l3), lk = d/dt + Ak with selfadjoint operator coefficients Ak in a Hilbert space. This is done as a direct sum of Hilbert spaces of vector-functions L2(H, (-∞, a1)) ⊕ L2(H, (a2, b2)) ⊕ L2(H, (a3,+∞)) where -∞ < a1 < a2 < b2 < a3 < +∞. Also, we study the structure of the spectrum of these extensions. [ABSTRACT FROM AUTHOR]

Published
2012

38. COMPACT INVERSES OF MULTIPOINT NORMAL DIFFERENTIAL OPERATORS FOR FIRST ORDER.

Author

ISMAILOV, ZAMEDDIN I., ÇEVIK, ELIF OTKUN, and UNLUYOL, ERDAL

Subjects
*OPERATOR theory, *DIFFERENTIAL equations, *HILBERT space, *BOUNDARY value problems, *INTERVAL analysis
Abstract

In this work, we describe all normal extensions of a multipoint minimal operators generated by linear multipoint differential-operator expressions for first order in the Hilbert space of vector functions, in terms of boundary values at the endpoints of infinitely many separated subintervals. Also we investigate compactness properties of the inverses of such extensions. [ABSTRACT FROM AUTHOR]

Published
2011

39. FIRST-ORDER SELFADJOINT SINGULAR DIFFERENTIAL OPERATORS IN A HILBERT SPACE OF VECTOR FUNCTIONS.

Author

IPEK, PEMBE, YILMAZ, BÜLENT, and ISMAILOV, ZAMEDDIN I.

Subjects
*DIFFERENTIAL operators, *VECTORS (Calculus), *HILBERT space, *COEFFICIENTS (Statistics), *GEOMETRY
Abstract

In this article, we give a representation of all selfadjoint extensions of the minimal operator generated by first-order linear symmetric multipoint singular differential expression, with operator coefficient in the direct sum of Hilbert spaces of vector-functions defined at the semi-infinite intervals. To this end we use the Calkin-Gorbachuk method. Finally, the geometry of spectrum set of such extensions is researched. [ABSTRACT FROM AUTHOR]

Published
2017

40. BOUNDEDLY SOLVABLE EXTENSIONS OF DELAY DIFFERENTIAL OPERATORS.

Author

GÜLER, BAHADIR Ö., YILMAZ, BÜLENT, and ISMAILOV, ZAMEDDIN I.

Subjects
*DELAY differential equations, *OPERATOR theory, *HILBERT space, *FUNCTIONAL differential equations, *LINEAR differential equations
Abstract

We describe all boundedly solvable extensions of minimal operators generated by first-order linear delay differential operators in Hilbert spaces of vector-functions on finite intervals. Also, we study the structure of spectrum of these extensions. To do this we use methods from operator theory. [ABSTRACT FROM AUTHOR]

Published
2017

41. Multipoint Selfadjoint Quasi-Differential Operators For First Order

Author

Zameddin I. Ismailov, Rukiye Öztürk Mert, Bülent Yılmaz, [Belirlenecek], Mert, Rukiye Ozturk, Yilmaz, Bulent, and Ismailov, Zameddin I.

Subjects
Pure mathematics, Symmetric and selfadjoint differential operators,multipoint quasi-differential expression,deficiency indices,spectrum, Direct sum, Mathematics::Operator Algebras, Spectrum (functional analysis), Structure (category theory), Hilbert space, [No Keywords], deficiency indices, General Medicine, Expression (computer science), multipoint quasi-differential expression, First order, Differential operator, spectrum, symbols.namesake, Operator (computer programming), symbols, Symmetric and selfadjoint differential operators, Mathematics
Abstract

In the present paper, the aim is to described all selfadjoint extensions of the minimal operator generated by Örst order linear symmetric multipoint quasi-di§erential operator expression in the direct sum of weighted Hilbert spaces of vector-functions deÖned at the semi-inÖnite intervals by using the Calkin-Gorbachuk method. We have also examine the structure of the spectrum of such extensions. WOS:000463698900081

Published
2019

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