Pełnotekstowe zasoby PLDML oraz innych baz dziedzinowych są już dostępne w nowej Bibliotece Nauki.
Zapraszamy na https://bibliotekanauki.pl
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 7

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  multipliers
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote

Interpolation by elementary operators

100%
Magajna B.
Studia Mathematica
|
1993
|
tom 105
|
nr 1
77-92
EN
Given two n-tuples $a = (a_1,...,a_n)$ and $b = (b_1,...,b_n)$ of bounded linear operators on a Hilbert space the question of when there exists an elementary operator E such that $Ea_j = b_j$ for all j =1,...,n, is studied. The analogous question for left multiplications (instead of elementary operators) is answered in any C*-algebra A, as a consequence of the characterization of closed left A-submodules in $A^n$.
2
Content available remote

Stabilité du spectre ponctuel d'opérateurs de Toeplitz généralisés

100%
Nikolskaia L.
Studia Mathematica
|
1995
|
tom 116
|
nr 1
1-22
EN
A general scheme based on a commutation relation is proposed to give rise to a definition of generalized Toeplitz operators on a Banach space. Under suitable conditions the existence of a symbol is proved and its continuation to algebras generated by generalized Toeplitz operators is constructed. A stability theorem for the point spectrum of an operator from generalized Toeplitz algebras is established; as examples one considers the standard and operator valued Toeplitz operators on weighted Hardy spaces and on spaces of functions (distributions) with weighted $l^p$ Fourier transforms.
3
Content available remote

Fourier transform, oscillatory multipliers and evolution equations in rearrangement invariant function spaces

100%
Brandolini L., Colzani L.
Colloquium Mathematicum
|
1996
|
tom 71
|
nr 2
273-286
4
Content available remote

Multipliers of Hardy spaces, quadratic integrals and Foiaş-Williams-Peller operators

100%
Blower G.
Studia Mathematica
|
1998
|
tom 131
|
nr 2
179-188
EN
We obtain a sufficient condition on a B(H)-valued function φ for the operator $⨍ ↦ Γ_φ ⨍'(S)$ to be completely bounded on $H^∞ B(H)$; the Foiaş-Williams-Peller operator | S^t Γ_φ | R_φ = | | | 0 S | is then similar to a contraction. We show that if ⨍ : D → B(H) is a bounded analytic function for which $(1-r) ||⨍'(re^{iθ})||^2_{B(H)} rdrdθ$ and $(1-r) ||⨍"(re^{iθ})||_{B(H)} rdrdθ$ are Carleson measures, then ⨍ multiplies $(H^1c^1)'$ to itself. Such ⨍ form an algebra A, and when φ'∈ BMO(B(H)), the map $⨍ ↦ Γ_φ ⨍'(S)$ is bounded $A → B(H^2(H), L^2(H) ⊖ H^2(H))$. Thus we construct a functional calculus for operators of Foiaş-Williams-Peller type.
5
Content available remote

Multipliers in Sobolev spaces and exact convergence rate estimates for the finite-difference schemes

100%
Jovanović B.
Banach Center Publications
|
1994
|
tom 29
|
nr 1
165-173
EN
In this paper we present some recent results concerning convergence rate estimates for finite-difference schemes approximating boundary-value problems. Special attention is given to the problem of minimal smoothness of coefficients in partial differential equations necessary for obtaining the results.
6
Content available remote

Operators on spaces of analytic functions

88%
Seddighi K.
Studia Mathematica
|
1994
|
tom 108
|
nr 1
49-54
EN
Let $M_z$ be the operator of multiplication by z on a Banach space of functions analytic on a plane domain G. We say that $M_z$ is polynomially bounded if $∥M_p∥ ≤ C∥p∥_G$ for every polynomial p. We give necessary and sufficient conditions for $M_z$ to be polynomially bounded. We also characterize the finite-codimensional invariant subspaces and derive some spectral properties of the multiplication operator in case the underlying space is Hilbert.
7
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Multipliers of topological algebras

77%
Husain T.
Instytut Matematyczny Polskiej Akademii Nauk
EN
CONTENTS 1. Introduction.............................................................................................5 2. Multipliers of topological algebras...........................................................6 3. Multipliers of topological algebras with orthogonal bases......................11 4. π-Algebras............................................................................................18 5. Orthogonal decomposition of topological algebras................................21 6. Π-Algebras associated with orthogonal decompositions........................24 7. Perturbation of orthogonal bases..........................................................27 8. Banach algebras with unconditional bases and multipliers....................31 References................................................................................................36
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.