English
Related papers

Related papers: Products of Unbounded Normal Operators

200 papers

We extend to multilinear Hankel operators the fact that some truncations of bounded Hankel operators are bounded. We prove and use a continuity property of bilinear Hilbert transforms on products of Lipschitz spaces and Hardy spaces.

Complex Variables · Mathematics 2016-09-07 Aline Bonami , Sandrine Grellier , Mohammad Kacim

We introduce a class of operators which is called unbounded Dunford-Pettis. In this paper, we study some properties of the operators, relationships with the other classes of operators and the space of these operators.

Functional Analysis · Mathematics 2019-09-25 Wang Zhangjun , Chen Zili , Chen Jinxi , Ouyang Miao

After an historical introduction on the standard algebraic approach to quantum mechanics of large systems we review the basic mathematical aspects of the algebras of unbounded operators. After that we discuss in some details their relevance…

Mathematical Physics · Physics 2009-04-01 Fabio Bagarello

The paper introduces unbounded antilinear operators on Hilbert spaces and develops their fundamental theory. In particular, we establish a closed range theorem, a polar decomposition theorem, and the convexity of the numerical range for…

Functional Analysis · Mathematics 2026-05-25 Arup Majumdar

An operator $T $ from a vector lattice $E$ into a normed lattice $F$ is called unbounded $\sigma$-order-to-norm continuous whenever $x_{n}\xrightarrow{uo}0$ implies $\| Tx_{n}\|\rightarrow 0$, for each sequence $(x_{n})_n\subseteq E$. For a…

Functional Analysis · Mathematics 2019-08-09 Mina Matin , Kazem Haghnejad Azar , Razi Alavizadeh

In this work we first give for PN spaces results parallel to those obtained by Egbert for the product of PM spaces, and generalize results by Alsina and Schweizer in order to study non-trivial products and the product of $m$-- transforms of…

Probability · Mathematics 2007-05-23 Bernardo Lafuerza-Guillen

We consider various systematic ways of defining unbounded operator valued integrals of complex functions with respect to (mostly) positive operator measures and positive sesquilinear form measures, and investigate their relationships to…

Functional Analysis · Mathematics 2014-02-28 Daniel Dubin , Jukka Kiukas , Juha-Pekka Pellonpää , Kari Ylinen

In this paper, we prove that the Cauchy integral operators (or Cauchy transforms) define continuous linear operators on the Smirnov classes for some certain domain with closed analytic boundary.

Functional Analysis · Mathematics 2018-09-05 Yüksel Soykan

We introduce unbounded multipliers on operator spaces. These multipliers generalize both, regular operators on Hilbert C*-modules and (bounded) multipliers on operator spaces.

Operator Algebras · Mathematics 2010-07-23 Hendrik Schlieter , Wend Werner

In this paper, we improve the famous Reid Inequality related to linear operators. Some monotony results for positive operators are also established with a different approach from what is known in the existing literature. Lastly, Reid and…

Functional Analysis · Mathematics 2017-07-12 Souheyb Dehimi , Mohammed Hichem Mortad

Applying a result of abstract ring theory we get that bijective additive mappings on standard algebras of unbounded operators preserving zero products are multiples of ring isomorphisms. The structure of additive bijective mappings on…

Operator Algebras · Mathematics 2007-05-23 Werner Timmermann

We discuss several open problems on spectrally bounded operators, some new, some old, adding in a few new insights.

Functional Analysis · Mathematics 2008-10-16 Martin Mathieu

By considering the general properties of approximate units in differentiable algebras, we are able to present a unified approach to characterising completeness of spectral metric spaces, existence of connections on modules, and the lifting…

Operator Algebras · Mathematics 2016-10-24 Bram Mesland , Adam Rennie

We introduce the class of unbounded $M$-weakly operators and the class of unbounded $L$-weakly compact operators. We investigate some properties for these new classification of operators and we study relation between them and $M$-weakly…

Functional Analysis · Mathematics 2021-09-16 Zahra Niktab , Kazem Haghnejad Azar , Razi Alavizadeh , Saba Sadeghi Gavgani

In this article the infinite product of bicomplex numbers is defined and the convergence and divergence of this product are discussed.

Complex Variables · Mathematics 2017-06-26 Chinmay Ghosh

In this paper, we introduce and study a new classes of operators, named AM-unbounded norm compact operators. We study the the basic properties of the new operator and we investigate the lattice-order and topology property of the operator…

Functional Analysis · Mathematics 2019-10-07 Wang Zhangjun , Chen Zili , Chen Jinxi

In the last decade, a large amount of research has been concentrated on the operators living on the model space. Asymmetric truncated Toeplitz operators and asymmetric truncated Hankel operators are the natural generalization of truncated…

Functional Analysis · Mathematics 2021-12-20 Ameur Yagoub , Muhammad Ahsan Khan

The primary purpose of this paper is to investigate the question of invertibility of the sum of operators. The setting is bounded and unbounded linear operators. Some interesting examples and consequences are given. As an illustrative…

Functional Analysis · Mathematics 2018-10-04 Mohammed Hichem Mortad

In this paper, we establish results about operators similar to their adjoints. This is carried out in the setting of bounded and also unbounded operators on a Hilbert space. Among the results, we prove that an unbounded closed operator…

Functional Analysis · Mathematics 2014-06-02 Souheyb Dehimi , Mohammed Hichem Mortad

A new class of operators, larger than $C$-symmetric operators and different than normal one, named $C$--normal operators is introduced. Basic properties are given. Characterizations of this operators in finite dimensional spaces using a…

Functional Analysis · Mathematics 2020-01-01 Marek Ptak , Katarzyna Simik , Anna Wicher