Yufeng Lu, Linghui Kong (2014)
Studia Mathematica
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We first determine when the sum of products of Hankel and Toeplitz operators is equal to zero; then we characterize when the product of a Toeplitz operator and a Hankel operator is a compact perturbation of a Hankel operator or a Toeplitz operator and when it is a finite rank perturbation of a Toeplitz operator.
Elżbieta Król-Klimkowska, Marek Ptak (2016)
Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica
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The investigation of properties of generalized Toeplitz operators with respect to the pairs of doubly commuting contractions (the abstract analogue of classical two variable Toeplitz operators) is proceeded. We especially concentrate on the condition of existence such a non-zero operator. There are also presented conditions of analyticity of such an operator.
Joanna Jurasik, Bartosz Łanucha (2016)
Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica
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Asymmetric truncated Toeplitz operators are compressions of multiplication operators acting between two model spaces. These operators are natural generalizations of truncated Toeplitz operators. In this paper we describe symbols of asymmetric truncated Toeplitz operators equal to the zero operator.
Albrecht Böttcher (1990)
Monatshefte für Mathematik
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Carmen H. Mancera, Pedro José Paúl (2001)
Czechoslovak Mathematical Journal
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In 1997 Pták defined generalized Hankel operators as follows: Given two contractions and , an operator is said to be a generalized Hankel operator if and satisfies a boundedness condition that depends on the unitary parts of the minimal isometric dilations of and . This approach, call it (P), contrasts with a previous one developed by Pták and Vrbová in 1988, call it (PV), based on the existence of a previously defined generalized Toeplitz operator. There seemed to be a strong...
Young Joo Lee (2023)
Czechoslovak Mathematical Journal
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A Coburn theorem says that a nonzero Toeplitz operator on the Hardy space is one-to-one or its adjoint operator is one-to-one. We study the corresponding problem for certain Toeplitz operators on the Bergman space.
Young Joo Lee (2015)
Studia Mathematica
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On the Hardy space of the unit disk, we consider operators which are finite sums of products of a Toeplitz operator and a Hankel operator. We then give characterizations for such operators to be zero. Our results extend several known results using completely different arguments.
Marek Ptak (2005)
Annales Polonici Mathematici
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Projections onto the spaces of all Toeplitz operators on the N-torus and the unit sphere are constructed. The constructions are also extended to generalized Toeplitz operators and applied to show hyperreflexivity results.
Miroslav Engliš, Jari Taskinen (2007)
Studia Mathematica
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It is well known that one can often construct a star-product by expanding the product of two Toeplitz operators asymptotically into a series of other Toeplitz operators multiplied by increasing powers of the Planck constant h. This is the Berezin-Toeplitz quantization. We show that one can obtain in a similar way in fact any star-product which is equivalent to the Berezin-Toeplitz star-product, by using instead of Toeplitz operators other suitable mappings from compactly supported smooth...
Foth, Tatyana (2007)
SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]
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Miroslav Engliš (1988)
Commentationes Mathematicae Universitatis Carolinae
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Aline Bonami, Joaquim Bruna (1999)
Publicacions Matemàtiques
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We study the boundedness properties of truncation operators acting on bounded Hankel (or Toeplitz) infinite matrices. A relation with the Lacey-Thiele theorem on the bilinear Hilbert transform is established. We also study the behaviour of the truncation operators when restricted to Hankel matrices in the Schatten classes.