Error controlled regularization by projection.
Nous donnons des résultats théoriques sur l’idéal de Macaev et la trace de Dixmier. Ensuite, nous caractérisons les symboles antiholomorphes tels que l’opérateur de Hankel sur l’espace de Bergman à poids soit dans l’idéal de Macaev et nous donnons la trace de Dixmier. Pour cela, nous regardons le comportement des normes de Schatten quand tend vers et nous nous appuyons sur le résultat de Engliš et Rochberg sur l’espace de Bergman. Nous parlons aussi des puissances de tels opérateurs. Abstract....
In this paper, we give some estimates for the essential norm and a new characterization for the boundedness and compactness of weighted composition operators from weighted Bergman spaces and Hardy spaces to the Bloch space.
Let and be holomorphic self-maps of the unit disk, and denote by , the induced composition operators. This paper gives some simple estimates of the essential norm for the difference of composition operators from Bloch spaces to Bloch spaces in the unit disk. Compactness of the difference is also characterized.
In this paper, we characterize boundedness and compactness of weighted composition operators on the Dirichlet space and obtain the estimates for the essential norm.
In 1999 Nina Zorboska and in 2003 P. S. Bourdon, D. Levi, S. K. Narayan and J. H. Shapiro investigated the essentially normal composition operator , when is a linear-fractional self-map of . In this paper first, we investigate the essential normality problem for the operator on the Hardy space , where is a bounded measurable function on which is continuous at each point of , , and is the Toeplitz operator with symbol . Then we use these results and characterize the essentially normal...
Let () be a compact set; assume that each ball centered on the boundary of meets in a set of positive Lebesgue measure. Let be the class of all continuously differentiable real-valued functions with compact support in and denote by the area of the unit sphere in . With each we associate the function of the variable (which is continuous in and harmonic in ). depends only on the restriction of to the boundary of . This gives rise to a linear operator acting from...
We complete the different cases remaining in the estimation of the essential norm of a weighted composition operator acting between the Hardy spaces and for 1 ≤ p,q ≤ ∞. In particular we give some estimates for the cases 1 = p ≤ q ≤ ∞ and 1 ≤ q < p ≤ ∞.