Results 51 to 60 of about 633 (85)

Inequalities for eigenvalues of compactly perturbed unitary operators

, 2017
We consider the operator A = U +K , where U is a unitary operator and K is a compact one. An eigenvalue λ of A is said to be a non-unitary one, if |λ | = 1 . We derive inequalities for sums of absolute values of the non-unitary eigenvalues.
M. Gil'
semanticscholar   +1 more source

A simple characterization of the trace‐class of operators

International Journal of Mathematics and Mathematical Sciences, Volume 4, Issue 2, Page 411-412, 1981., 1981
The trace‐class (τc) of operators on a Hilbert space is characterized in terms of existence of certain centralizers.
Parfeny P. Saworotnow
wiley   +1 more source

On Lipschitz functions of normal operators

, 1985
It is shown that if N and M are normal operators on a separable, complex Hubert space H, and/is a Lipschitz function on Q = a(N) U a(M) (i.e., \f(z) — f(w)\ ,.||2)1/2 be the Hilbert-Schmidt norm of T.
F. Kittaneh
semanticscholar   +1 more source

Generalized Derivations and Norm Equality in Normed Ideals [PDF]

, 2011
2000 Mathematics Subject Classification: 47A10, 47A12, 47A30, 47B10, 47B20, 47B37, 47B47, 47D50.We compare the norm of a generalized derivation on a Hilbert space with the norm of its restrictions to Schatten norm ...
Barraa, Mohamed
core  

Some Hermite-Hadamard type integral inequalities for operator AG-preinvex functions

Acta Universitatis Sapientiae: Mathematica, 2016
In this paper, we introduce the concept of operator AG-preinvex functions and prove some Hermite-Hadamard type inequalities for these functions. As application, we obtain some unitarily invariant norm inequalities for operators.
Taghavi Ali, Nazari Haji Mohammad, Darvish Vahid   +2 more
doaj   +1 more source

On p-Compact Sets in Classical Banach Spaces

, 2014
Given p ≥ 1, we denote by Cp the class of all Banach spaces X satisfying the equality Kp(Y,X) = Πp(Y,X) for every Banach space Y , Kp (respectively, Πp) being the operator ideal of p-compact operators (respectively, of operators with p-summing adjoint ...
J. M. Delgado, C. Piñeiro
semanticscholar   +1 more source

Schatten p-norm inequalities related to a characterization of inner product spaces

, 2008
Let $A_1, ... A_n$ be operators acting on a separable complex Hilbert space such that $\sum_{i=1}^n A_i=0$. It is shown that if $A_1, ... A_n$ belong to a Schatten $p$-class, for some $p>0$, then 2^{p/2}n^{p-1} \sum_{i=1}^n \|A_i\|^p_p \leq \sum_{i,j=1 ...
Hirzallah, O., Kittaneh, F., Moslehian, M. S.   +2 more
core   +2 more sources

On the weak limit of compact operators on the reproducing kernel Hilbert space and related questions

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2016
By applying the so-called Berezin symbols method we prove a Gohberg- Krein type theorem on the weak limit of compact operators on the non- standard reproducing kernel Hilbert space which essentially improves the similar results of Karaev [5]: We also in ...
Saltan Suna
doaj   +1 more source

On critical points of Blaschke products [PDF]

, 2010
We obtain an upper bound for the derivative of a Blaschke product, whose zeros lie in a certain Stolz-type region. We show that the derivative belongs to the space of analytic functions in the unit disk, introduced recently in \cite{FG}.
Favorov, S., Golinskii, L.
core  

(q, p)-Mixing Bloch maps

Demonstratio Mathematica
As a Bloch variant of (q,p)\left(q,p)-mixing linear operators, we introduce the notion of (q,p)\left(q,p)-mixing Bloch maps. We prove Pietsch’s domination theorem and Maurey’s splitting theorem in this Bloch context, following the corresponding results ...
Jiménez-Vargas Antonio, Ruiz-Casternado David   +1 more
doaj   +1 more source