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This paper provides a class of complex symmetric weighted composition operators on $H^2(\mathbb{D})$ to includes the unitary subclass, the Hermitian subclass and the normal subclass obtained by Bourdon and Noor. A characterization of…

Functional Analysis · Mathematics 2018-12-27 Cao Jiang , Shi-An Han , Ze-Hua Zhou

For some time now, conformal field theories in two dimensions have been studied as integrable systems. Much of the success of these studies is related to the existence of an operator algebra of the theory. In this paper, some of the…

High Energy Physics - Theory · Physics 2009-11-11 Jasbir Nagi

It is proved recently by Benamara-Nikolski that a contraction having finite defects and spectrum not filling in the closed unit disc, is similar to a normal operator if and only if it has the so-called linear resolvent growth property. We…

Spectral Theory · Mathematics 2007-05-23 Stanislav Kupin

In this paper we firstly introduce the concepts of capacity and Cegrell's classes associated to any $m$-positive closed current $T$. Next, after investigating the most imporant related properties, we study the definition and the continuity…

Complex Variables · Mathematics 2015-04-15 Abir Dhouib , Fredj Elkhadhra

Recent advances in the theory of complex symmetric operators are presented and related to current studies in non-hermitian quantum mechanics. The main themes of the survey are: the structure of complex symmetric operators, $C$-selfadjoint…

Functional Analysis · Mathematics 2014-09-17 Stephan Ramon Garcia , Emil Prodan , Mihai Putinar

Let $X$ be a complex topological vector space with dim$(X)>1$ and $\mathcal{B}(X)$ the space of all continuous linear operators on $X$. In this paper, we extend the concept of supercyclicity of a single operators and strongly continuous…

Functional Analysis · Mathematics 2018-10-18 Mohamed Amouch , Otmane Benchiheb

It is shown that a large class of properties coincide for weighted composition operators on a large class of weighted VMOA spaces, including the ones with logarithmic weights and the ones with standard weights $(1-|z|)^{-c}, \ 0\leq c<…

Functional Analysis · Mathematics 2025-04-16 David Norrbo

We give necessary and sufficient conditions for a bounded operator defined between complex Hilbert spaces to be absolutely norm attaining. We discuss structure of such operators in the case of self-adjoint and normal operators separately.…

Spectral Theory · Mathematics 2018-01-09 G. Ramesh , D. Venku Naidu

In this article, we impose a new class of fractional analytic functions in the open unit disk. By considering this class, we define a fractional operator, which is generalized Salagean and Ruscheweyh differential operators. Moreover, by…

Complex Variables · Mathematics 2016-02-26 Zainab E. Abdulnaby , Rabha W. Ibrahim , Adem Kilicman

Many studies have been conducted on statistical convergence, and it remains an area of active research. Since its introduction, statistical convergence has found applications many fields. Nevertheless, there is a shortage of research…

Functional Analysis · Mathematics 2024-06-14 Erdal Bayram , Mehmet Küçükaslan , Mikail Et , Abdullah Aydın

We state several equivalent noncommutative versions of the Cauchy-Riemann equations and characterize the unbounded operators on L^2(R) which satisfy them. These operators arise from the creation operator via a functional calculus involving…

Operator Algebras · Mathematics 2007-05-23 Richard Rochberg , Nik Weaver

Let $A$ and $B$ be two densely defined unbounded closeable operators in a Hilbert space such that their unbounded operator products $AB$ and $BA$ are also densely defined. Then all four operators possess adjoints and we obtain new inclusion…

Functional Analysis · Mathematics 2013-12-23 Karl Gustafson , Mohammed Hichem Mortad

Covering ill-posed problems with compact and non-compact operators regarding the degree of ill-posedness is a never ending story written by many authors in the inverse problems literature. This paper tries to add a new narrative and some…

Numerical Analysis · Mathematics 2024-11-27 Frank Werner , Bernd Hofmann

A formalism for the study of highly interacting electronic systems is presented. The proposed scheme is based on two key concepts: composite operators and algebra constraints. Composite field operators, that naturally appear as a…

Strongly Correlated Electrons · Physics 2009-11-10 Ferdinando Mancini

Complementable operators extend classical matrix decompositions, such as the Schur complement, to the setting of infinite-dimensional Hilbert spaces, thereby broadening their applicability in various mathematical and physical contexts. This…

Functional Analysis · Mathematics 2025-01-14 Sachin Manjunath Naik , P. Sam Johnson

We characterize the spectrum (and its parts) of operators which can be represented as G=A+BC for a simpler operator A and a structured perturbation BC. The interest in this kind of perturbations is motivated, e.g., by perturbations of the…

Spectral Theory · Mathematics 2016-10-05 Martin Adler , Klaus-Jochen Engel

In this paper, a new axiomatization for unbounded functional calculi is proposed and the associated theory is elaborated comprising, among others, uniqueness and compatibility results and extension theorems of algebraic and topological…

Functional Analysis · Mathematics 2020-09-11 Markus Haase

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

Some results on fixed points related to the contractive compositions of bounded operators in complete metric spaces are discussed through the manuscript. The class of composite operators under study can include, in particular, sequences of…

Functional Analysis · Mathematics 2012-08-30 M. De la Sen

In this paper, we first study the definition and the continuity of the complex Hessian operator associated to an $m$-positive closed current $T$, for some classes of unbounded $m$-subharmonic functions as well as when we consider a…

Complex Variables · Mathematics 2021-05-18 Hadhami Elaini , Fredj Elkhadhra
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