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Related papers: Some examples of EP operators

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We reconsider studies of Toeplitz operators on function spaces (the weighted Bergman space, the generalized derivative Hardy space) and the H-Toeplitz operators on the Bergman space. Past studies have considered the presence or absence of…

Functional Analysis · Mathematics 2024-09-20 Chafiq Benhida , George R. Exner , Ji Eun Lee , Jongrak Lee

Boundedness results for multilinear pseudodifferential operators on products of modulation spaces are derived based on ordered integrability conditions on the short-time Fourier transform of the operators' symbols. The flexibility and…

Functional Analysis · Mathematics 2015-02-12 Shahla Molahajloo , Kasso A. Okoudjou , Götz E. Pfander

This article introduces several new relations among related Hilbert space operators. In particular, we prove some L\"{o}ewner partial orderings among $T, |T|, \mathcal{R}T, \mathcal{I}T, |T|+|T^*|$ and many other related forms, as a new…

Functional Analysis · Mathematics 2023-03-08 Mohammad Sababheh , Hamid Reza Moradi

The defining characteristic of an exceptional point (EP) in the parameter space of a family of operators is that upon encircling the EP eigenstates are permuted. In case one encircles multiple EPs, the question arises how to properly…

Mathematical Physics · Physics 2018-08-29 Eric J. Pap , Daniël Boer , Holger Waalkens

In this paper, we derive a generalized multiplicative Hardy-Littlewood-Polya type inequality, as well as several related additive inequalities, for functions of operators in Hilbert spaces. In addition, we find the modulus of continuity of…

Functional Analysis · Mathematics 2015-10-06 Vladyslav Babenko , Yuliya Babenko , Nadiia Kriachko

In this work, generalization of some inequalities for continuous $h$-synchronous ($h$-asynchronous) functions of selfadjoint linear operators in Hilbert spaces are proved.

Functional Analysis · Mathematics 2017-12-20 Mohammad W. Alomari

Motivated by potential theory on discrete spaces, we study a family of unbounded Hermitian operators in Hilbert space which generalize the usual graph-theoretic discrete Laplacian. These operators are discrete analogues of the classical…

Functional Analysis · Mathematics 2011-02-01 Palle E. T. Jorgensen , Erin P. J. Pearse

We consider two operator space versions of type and cotype, namely $S_p$-type, $S_q$-cotype and type $(p,H)$, cotype $(q,H)$ for a homogeneous Hilbertian operator space $H$ and $1\leq p \leq 2 \leq q\leq \infty$, generalizing "$OH$-cotype…

Functional Analysis · Mathematics 2007-05-23 Hun Hee Lee

Let $X$ be a right Hilbert module over a $C^*$-algebra $A$ equipped with the canonical operator space structure. We define an elementary operator on $X$ as a map $\phi : X \to X$ for which there exists a finite number of elements $u_i$ in…

Operator Algebras · Mathematics 2020-01-13 Ljiljana Arambašić , Ilja Gogić

We introduce the good Hilbert functor and prove that it is algebraic. This functor generalizes various versions of the Hilbert moduli problem, such as the multigraded Hilbert scheme and the invariant Hilbert scheme. Moreover, we generalize…

Algebraic Geometry · Mathematics 2016-11-04 Gustav Sædén Ståhl

We solve a number of questions pertaining to the dynamics of linear operators on Hilbert spaces, sometimes by using Baire category arguments and sometimes by constructing explicit examples. In particular, we prove the following results. - A…

Functional Analysis · Mathematics 2017-03-07 Sophie Grivaux , Etienne Matheron , Quentin Menet

We give a spectral theorem for unital representations of Hermitian commutative unital *-algebras by possibly unbounded operators in a pre-Hilbert space. A better result is known for the case in which the *-algebra is countably generated.

Operator Algebras · Mathematics 2024-11-13 Marco Thill

In this article we prove some Lipschitz estimates and existence result for a class of degenerate fully nonlinear elliptic equations which are a generalization of the pseudo p-Laplacian. The operators are degenerate elliptic at any point…

Analysis of PDEs · Mathematics 2019-07-23 Isabeau Birindelli , Francoise Demengel

In this article we consider a class of non-degenerate elliptic operators obtained by superpositioning the Laplacian and a general nonlocal operator. We study the existence-uniqueness results for Dirichlet boundary value problems, maximum…

Analysis of PDEs · Mathematics 2023-10-11 Anup Biswas , Mitesh Modasiya

We give new examples of weak Hilbert spaces.

Functional Analysis · Mathematics 2007-05-23 George Androulakis , Peter G. Casazza , Denka N. Kutzarova

In this paper we investigate the parallelization of two modular algorithms. In fact, we consider the modular computation of Gr\"obner bases (resp. standard bases) and the modular computation of the associated primes of a zero-dimensional…

Commutative Algebra · Mathematics 2011-03-14 Nazeran Idrees , Gerhard Pfister , Stefan Steidel

We study extendibility of diagonal multilinear operators from $\ell_p$ to $\ell_q$ spaces. We determine the values of $p$ and $q$ for which every diagonal $n$-linear operator is extendible, and those for which the only extendible ones are…

Functional Analysis · Mathematics 2014-03-19 Daniel Carando , Verónica Dimant , Pablo Sevilla-Peris , Román Villafañe

This article is devoted to studying some new numerical radius inequalities for Hilbert space operators. Our analysis enables us to improve an earlier bound of numerical radius due to Kittaneh.

Functional Analysis · Mathematics 2020-09-22 Mahdi Ghasvareh , Mohsen Erfanian Omidvar

Iterates of quantum operations and their convergence are investigated in the context of mean ergodic theory. We discuss in detail the convergence of the iterates and show that the uniform ergodic theorem plays an essential role. Our results…

Mathematical Physics · Physics 2022-06-14 J. Z. Bernád

In this paper, we show several bounds for the numerical radius of a Hilbert space operator in terms of the Euclidean operator norm. The obtained forms will enable us to find interesting refinements of celebrated results in the literature.…

Functional Analysis · Mathematics 2023-09-21 Mohammad Sababheh , Hamid Reza Moradi , Mohammad Alomari