Results 31 to 40 of about 554 (59)

Hyponormality of finite rank perturbations of normal operators

, 2018
Let T be an arbitrary finite rank perturbation of a normal operator N acting on a separable, infinite dimensional, complex Hilbert space H . It is proved that the hyponormality and normality of T are equivalent.
I. Jung, Eun-Young Lee, M. Seo
semanticscholar   +1 more source

Almost invariant half-spaces for operators on Hilbert space. II: operator matrices

, 2017
This paper is a sequel to [6]. In that paper we transferred the discussions in [1] and [13] concerning almost invariant half-spaces for operators on complex Banach spaces to the context of operators on Hilbert space, and we gave easier proofs of the main
Jung, Il Bong, Ko, Eungil, Pearcy, Carl
core   +1 more source

Remarks on „Weak limits of almost invariant projections” by Foias, Pasnicu and Voiculescu

, 2017
Ultraproducts of operators are used to give simpler proofs of certain results in the paper “Weak limits of almost invariant projections” by Foias, Pasnicu and Voiculescu. Mathematics subject classification (2010): 47A15, 47A58.
M. Boedihardjo
semanticscholar   +1 more source

Canonical decomposition of operators associated with the symmetrized polydisc

, 2017
A tuple of commuting operators $(S_1,\dots,S_{n-1},P)$ for which the closed symmetrized polydisc $\Gamma_n$ is a spectral set is called a $\Gamma_n$-contraction.
Pal, Sourav
core   +2 more sources

Ideal-triangularizability and commutators of constant sign

, 2016
Let E be a Banach lattice with order continuous norm, and let A and B be positive compact operators such that the commutator AB−BA is also positive. We prove that if A and B are ideal-triangularizable, then they are simultaneously ideal-triangularizable,
R. Drnovšek, M. Kandić
semanticscholar   +1 more source

Canonical decomposition of a tetrablock contraction and operator model

, 2016
A triple of commuting operators for which the closed tetrablock $\overline{\mathbb E}$ is a spectral set is called a tetrablock contraction or an $\mathbb E$-contraction. The set $\mathbb E$ is defined as \[ \mathbb E = \{ (x_1,x_2,x_3)\in\mathbb C^3\,:\,
Pal, Sourav
core   +1 more source

Idempotent vector spaces and their linear transformations

Concrete Operators
This article extends topics about linear algebra and operator theoretic linear transformations on complex vector spaces to those on bicomplex spaces.
Johnston William, Wahl Rebecca G.
doaj   +1 more source

Fe₃O₄@SiO₂-NH₂ Functionalized Nanoparticles as a Potential Contrast Agent in Magnetic Resonance

Condensed Matter
The present work proposes a method for the synthesis of a nanoparticle with a superparamagnetic Fe3O4 core coated with SiO2-NH2 by ultrasound-assisted coprecipitation.
Brayan Stick Betin Bohorquez, Indry Milena Saavedra Gaona, Carlos Arturo Parra Vargas, Karina Vargas-Sánchez, Jahaziel Amaya, Mónica Losada-Barragán, Javier Rincón, Daniel Llamosa Pérez   +7 more
doaj   +1 more source

Closed ideals in some algebras of analytic functions

, 2008
We obtain a complete description of closed ideals of the algebra $\mathcal{D}\cap \mathrm{lip}_\alpha ...
Brahim Bouya, Carleson, El-Fallah, Esterle, Hedenmalm, Hoffman, Korenbljuum, Matheson, Shamoyan, Shirokov, Taylor   +10 more
core   +1 more source

Class A operators and their extensions

, 2013
In this paper, we study various properties of analytic extensions of class A operators. In particular, we show that every analytic extension of a class A operator has a scalar extension. As a corollary, we get that such an operator with rich spectrum has
Sungeun Jung, Eungil Ko
semanticscholar   +1 more source