Let A(D) be the disc algebra of all continuous complex-valued functions on the unit disc D holomorphic in its interior. Functions from A(D) act on the set of all contraction operators (‖A‖ 1) on Hilbert spaces. It is proved that the following classes of functions from A(D) coincide: (1) the class of operator Lipschitz functions on the unit circle T; (2) the class of operator Lipschitz functions...

For a neutral functional differential equation with a stable operator, D, it is shown that the solution operator is the sum of a contraction and a completely continuous operator.

The main purpose of this paper is to prove the intuitionistic fuzzy contraction properties of the Hutchinson-Barnsley operator on the intuitionistic fuzzy hyperspace with respect to the Hausdorff intuitionistic fuzzy metrics. Also we discuss about the relationships between the Hausdorff intuitionistic fuzzy metrics on the intuitionistic fuzzy hyperspaces. Our theorems generalize and extend some...

In belief revision, the result of a contraction should be a logically closed set (closure) such that the input is not inferred (success). Traditionally, these two postulates depend on the same consequence operator. The present work investigates the consequences of using two different consequence operators for each of these desiderata: the classic Cn to compute success and a second weaker operat...

for a ∈ mn, the schur multiplier of a is defined as s a(x) =a ◦ x for all x ∈ mn and the spectral norm of s a can be stateas ∥s a∥ = supx,0 ∥a ∥x ◦x ∥ ∥. the other norm on s a can be definedas ∥s a∥ω = supx,0 ω(ω s( ax (x ) )) = supx,0 ωω (a (x ◦x ) ), where ω(a) standsfor the numerical radius of a. in this paper, we focus on therelation between the norm of schur multiplier of product of matric...

We study the generalization of m-isometries and m-contractions (for positive integers m) to what we call a-isometries a-contractions for real numbers a. show that an operator satisfying a certain inequality in hereditary form is similar a-contraction. This improvement [9, Theorem I] based on some Banach algebras techniques. our classes are closely connected with fractional finite differences. U...

The purpose of the present notes is to examine following issues related Chernoff estimate: (1) For contractions on a Banach space we modify $\sqrt{n}$-estimate and apply it in proof product formula for $C_0$-semigroups \textit{strong} operator topology. (2) We use idea {probabilistic} approach, proving estimate strong topology, uplift \textit{operator-norm} \textit{quasi-sectorial} contraction ...

We consider the composition of random i.i.d. aane maps of a Hilbert space to itself. We show convergence of the n'th composition in the Wasserstein metric via a contraction argument. The contraction condition involves the operator norm of the expectation of a bilinear form. This is contrasted with the usual contraction condition of a negative Lyapunov exponent. Our condition is stronger but eas...