Results 1 to 10 of about 394 (31)

Operator Subadditivity of the 𝒟-Logarithmic Integral Transform for Positive Operators in Hilbert Spaces

open access: yesAnnales Mathematicae Silesianae, 2021
For a continuous and positive function ω (λ); λ> 0 and μ a positive measure on [0; ∞) we consider the following 𝒟-logarithmic integral transform𝒟ℒog(w,μ)(T):=∫0∞w(λ)1n(λ+Tλ)dμ(λ),\mathcal{D}\mathcal{L}og\left( {w,\mu } \right)\left( T \right): = \int_0 ...
Dragomir Silvestru Sever
doaj   +1 more source

Spectrum and Analytic Functional Calculus for Clifford Operators via Stem Functions

open access: yesConcrete Operators, 2021
The main purpose of this work is the construction of an analytic functional calculus for Clifford operators, which are operators acting on certain modules over Clifford algebras.
Vasilescu Florian-Horia
doaj   +1 more source

Gradient Inequalities for an Integral Transform of Positive Operators in Hilbert Spaces

open access: yesAnnales Mathematicae Silesianae, 2023
For a continuous and positive function w (λ) , λ > 0 and µ a positive measure on (0, ∞) we consider the following integral transform 𝒟(w,μ)(T):=∫0∞w(λ)(λ+T)-1dμ(λ),\mathcal{D}\left( {w,\mu } \right)\left( T \right): = \int_0^\infty {w\left( \lambda ...
Dragomir Silvestru Sever
doaj   +1 more source

On a class of shift-invariant subspaces of the Drury-Arveson space

open access: yesConcrete Operators, 2018
In the Drury-Arveson space, we consider the subspace of functions whose Taylor coefficients are supported in a set Y⊂ ℕd with the property that ℕ\X + ej ⊂ ℕ\X for all j = 1, . . . , d.
Arcozzi Nicola, Levi Matteo
doaj   +1 more source

Functional calculus for $C_0$-semigroups using infinite-dimensional systems theory [PDF]

open access: yes, 2015
In this short note we use ideas from systems theory to define a functional calculus for infinitesimal generators of strongly continuous semigroups on a Hilbert space.
Schwenninger, Felix, Zwart, Hans
core   +2 more sources

On further refinements for Young inequalities

open access: yesOpen Mathematics, 2018
In this paper sharp results on operator Young’s inequality are obtained. We first obtain sharp multiplicative refinements and reverses for the operator Young’s inequality.
Furuichi Shigeru, Moradi Hamid Reza
doaj   +1 more source

The Cayley transform of Banach algebras

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 29, Issue 7, Page 427-428, 2002., 2002
The main result of Haynes (1991) is that a square matrix is convergent (limn→∞Dn = 0) if and only if it is the Cayley transform CA = (I−A)−1(I + A) of a stable matrix A. In this note, we show, with a simple proof, that the above is true in a much more general setting of complex Banach algebras.
Zhidong Pan
wiley   +1 more source

Continuity and general perturbation of the Drazin inverse for closed linear operators

open access: yesAbstract and Applied Analysis, Volume 7, Issue 6, Page 335-347, 2002., 2002
We study perturbations and continuity of the Drazin inverse of a closed linear operator A and obtain explicit error estimates in terms of the gap between closed operators and the gap between ranges and nullspaces of operators. The results are used to derive a theorem on the continuity of the Drazin inverse for closed operators and to describe the ...
N. Castro González   +2 more
wiley   +1 more source

Regularized functional calculi, semigroups, and cosine functions for pseudodifferential operators

open access: yesAbstract and Applied Analysis, Volume 2, Issue 1-2, Page 121-136, 1997., 1997
Let iAj(1 ≤ j ≤ n) be generators of commuting bounded strongly continuous groups, A ≡ (A1, A2, …, An). We show that, when f has sufficiently many polynomially bounded derivatives, then there exist k, r > 0 such that f(A) has a ‐regularized BCk(f(Rn)) functional calculus.
Ralph Delaubenfels, Yansong Lei
wiley   +1 more source

Estimates for Tsallis relative operator entropy [PDF]

open access: yes, 2017
We give the tight bounds of Tsallis relative operator entropy by using Hermite-Hadamard's inequality. Some reverse inequalities related to Young inequalities are also given.
Furuichi, Shigeru   +2 more
core   +1 more source

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