Singular sets and number of solutions of nonlinear boundary value problems
Singular Value Estimates for Certain Convolution-Product Operators.
Slant Hankel operators
In this paper the notion of slant Hankel operator , with symbol in , on the space , being the unit circle, is introduced. The matrix of the slant Hankel operator with respect to the usual basis of the space is given by , where is the Fourier expansion of . Some algebraic properties such as the norm, compactness of the operator are discussed. Along with the algebraic properties some spectral properties of such operators are discussed. Precisely, it is proved that for an invertible...
Slowly oscillating perturbations of periodic Jacobi operators in l²(ℕ)
We prove that the absolutely continuous part of the periodic Jacobi operator does not change (modulo unitary equivalence) under additive perturbations by compact Jacobi operators with weights and diagonals defined in terms of the Stolz classes of slowly oscillating sequences. This result substantially generalizes many previous results, e.g., the one which can be obtained directly by the abstract trace class perturbation theorem of Kato-Rosenblum. It also generalizes several results concerning perturbations...
Small ball properties for Fréchet spaces.
We give characterizations of certain properties of continuous linear maps between Fréchet spaces, as well as topological properties on Fréchet spaces, in terms of generalizations of Behrends and Kadets small ball property.
Small bound isomorphisms of the domain of a closed *-derivation.
Small ideals of operators
Small operators between Banach and Hilbert spaces
Small sets and hypercyclic vectors
We study the ``smallness'' of the set of non-hypercyclic vectors for some classical hypercyclic operators.
Smooth operators and commutators
Smooth operators in the commutant of a contraction
For a completely non-unitary contraction T, some necessary (and, in certain cases, sufficient) conditions are found for the range of the calculus, , and the commutant, T’, to contain non-zero compact operators, and for the finite rank operators of T’ to be dense in the set of compact operators of T’. A sufficient condition is given for T’ to contain non-zero operators from the Schatten-von Neumann classes .
s-numbers, eigenvalues and the trace theorem in Banach spaces
s-numbers of diagonal operators and Besov embeddings
s-Numbers of operators in Banach spaces
Sobolev multipliers
Sobolev- und Sobolev-Hardy-Räume auf S1: Dualitätstheorie und Funktionalkalküle.
Sobre algunas propiedades de espacios de Banach.
Sobre el espectro de derivaciones y automorfismos de las álgebras de Banach.
Sobre la estructura de los espacios de operadores de Lorentz.
Sobre la topología débil en componentes del ideal de los operadores p-compactos de Saphar con 1 < p < ∞.