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Eigenvalues of Hille-Tamarkin operators and geometry of Banach function spaces

Thomas Kühn, Mieczysław Mastyło (2011)

Studia Mathematica

We investigate how the asymptotic eigenvalue behaviour of Hille-Tamarkin operators in Banach function spaces depends on the geometry of the spaces involved. It turns out that the relevant properties are cotype p and p-concavity. We prove some eigenvalue estimates for Hille-Tamarkin operators in general Banach function spaces which extend the classical results in Lebesgue spaces. We specialize our results to Lorentz, Orlicz and Zygmund spaces and give applications to Fourier analysis. We are also...

Espace de Dixmier des opérateurs de Hankel sur les espaces de Bergman à poids

Romaric Tytgat (2015)

Czechoslovak Mathematical Journal

Nous donnons des résultats théoriques sur l’idéal de Macaev et la trace de Dixmier. Ensuite, nous caractérisons les symboles antiholomorphes f ¯ tels que l’opérateur de Hankel H f ¯ 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 𝒮 p quand p tend vers 1 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....

Essential norms of weighted composition operators on the space of Dirichlet series

Pascal Lefèvre (2009)

Studia Mathematica

We estimate the essential norm of a weighted composition operator relative to the class of Dunford-Pettis operators or the class of weakly compact operators, on the space of Dirichlet series. As particular cases, we obtain the precise value of the generalized essential norm of a composition operator and of a multiplication operator.

Exact asymptotic behavior of singular values of a class of integral operators

Milutin R. Dostanić (1999)

Czechoslovak Mathematical Journal

We find an exact asymptotic formula for the singular values of the integral operator of the form Ω T ( x , y ) k ( x - y ) · d y L 2 ( Ω ) L 2 ( Ω ) ( Ω m , a Jordan measurable set) where k ( t ) = k 0 ( ( t 1 2 + t 2 2 + ... t m 2 ) m 2 ) , k 0 ( x ) = x α - 1 L ( 1 x ) , 1 2 - 1 2 m < α < 1 2 and L is slowly varying function with some additional properties. The formula is an explicit expression in terms of L and T .

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