Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "bounded operators" wg kryterium: Wszystkie pola

  Lista filtrów
Wyrównaj
Wyświetlanie 1-25 z 45
Tytuł:
Algebraic polynomially bounded operators
Autorzy:
Mlak, W.
Powiązania:
https://bibliotekanauki.pl/articles/716527.pdf
Data publikacji:
1974
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Źródło:
Annales Polonici Mathematici; 1974-1975, 29, 2; 133-139
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the mean ergodic theorem for Cesàro bounded operators
Autorzy:
Derriennic, Yves
Powiązania:
https://bibliotekanauki.pl/articles/965638.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
For a Cesàro bounded operator in a Hilbert space or a reflexive Banach space the mean ergodic theorem does not hold in general. We give an additional geometrical assumption which is sufficient to imply the validity of that theorem. Our result yields the mean ergodic theorem for positive Cesàro bounded operators in $L^{p}$ (1 < p < ∞). We do not use the tauberian theorem of Hardy and Littlewood, which was the main tool of previous authors. Some new examples, interesting for summability theory, are described: we build an example of a mean ergodic operator T in a Hilbert space such that $∥T^{n}∥/n$ does not converge to 0, and whose adjoint operator is not mean ergodic (its Cesàro averages converge only weakly).
Źródło:
Colloquium Mathematicum; 2000, 84/85, 2; 443-455
0010-1354
Pojawia się w:
Colloquium Mathematicum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the growth of the resolvent operators for power bounded operators
Autorzy:
Nevanlinna, Olavi
Powiązania:
https://bibliotekanauki.pl/articles/1358683.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
Outline. In this paper I discuss some quantitative aspects related to power bounded operators T and to the decay of $T^{n}(T-1)$. For background I refer to two recent surveys J. Zemánek [1994], C. J. K. Batty [1994]. Here I try to complement these two surveys in two different directions. First, if the decay of $T^{n}(T-1)$ is as fast as O(1/n) then quite strong conclusions can be made. The situation can be thought of as a discrete version of analytic semigroups; I try to motivate this in Section 1 by demonstrating the similarity and lack of it between power boundedness of T and uniform boundedness of $e^{t(cT-1)}$ where c is a constant of modulus 1 and t > 0. Section 2 then contains the main result in this direction. I became interested in studying the quantitative aspects of the decay of $T^{n}(T-1)$ since it can be used as a simple model for what happens in the early phase of an iterative method (O. Nevanlinna [1993]). Secondly, the so called Kreiss matrix theorem relates bounds for the powers to bounds for the resolvent. The estimate is proportional to the dimension of the space and thus has as such no generalization to operators. However, qualitatively such a result holds in Banach spaces e.g. for Riesz operators: if the resolvent satisfies the resolvent condition, then the operator is power bounded operator (but without an estimate). I introduce in Section 3 a growth function for bounded operators. This allows one to obtain a result of the form: if the resolvent condition holds and if the growth function is finite at 1, then the powers are bounded and can be estimated. In Section 4 in addition to the Kreiss matrix theorem, two other applications of the growth function are given.
Źródło:
Banach Center Publications; 1997, 38, 1; 247-264
0137-6934
Pojawia się w:
Banach Center Publications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unbounded well-bounded operators, strongly continuous semigroups and the Laplace transform
Autorzy:
deLaubenfels, Ralph
Powiązania:
https://bibliotekanauki.pl/articles/1293082.pdf
Data publikacji:
1992
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
Suppose A is a (possibly unbounded) linear operator on a Banach space. We show that the following are equivalent. (1) A is well-bounded on [0,∞). (2) -A generates a strongly continuous semigroup ${e^{-sA}}_{s≤0}$ such that ${(1/s^2)e^{-sA}}_{s>0}$ is the Laplace transform of a Lipschitz continuous family of operators that vanishes at 0. (3) -A generates a strongly continuous differentiable semigroup ${e^{-sA}}_{s≥0}$ and ∃ M < ∞ such that $∥H_n(s)∥ ≡ ∥(∑_{k=0}^n (s^k A^{k})/k!) e^{-sA}∥ ≤ M$, ∀s > 0, n ∈ ℕ ∪ {0}. (4) -A generates a strongly continuous holomorphic semigroup ${e^{-zA}}_{Re(z)>0}$ that is O(|z|) in all half-planes Re(z) > a > 0 and $K(t) ≡ ʃ_{1+iℝ} e^{zt} e^{-zA} dz/(2πiz^3)$ defines a differentiable function of t, with Lipschitz continuous derivative, with K'(0) = 0. We may then construct a decomposition of the identity, F, for A, from K(t) or $H_n(s)$. For ϕ ∈ X*, x ∈ X, $(F(t)ϕ)(x) = (d/dt)^2 (ϕ(K(t)x)) = lim_{n→∞} ϕ(H_n(n/t)x)$, for almost all t.
Źródło:
Studia Mathematica; 1992, 103, 2; 143-159
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Maximal abelian subalgebras of \(B(\mathcal{X})\)
Autorzy:
Bračič, Janko
Kuzma, Bojan
Powiązania:
https://bibliotekanauki.pl/articles/746718.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Abelian algebra
Bounded operators
Complex Banach space
Opis:
Let \(\mathcal{X}\) be an infinite dimensional complex Banach space and \(B(\mathcal{X})\) be the Banach algebra of all bounded linear operators on \(\mathcal{X}\). Żelazko [1] posed the following question: Is it possible that some maximal abelian subalgebra of \(B(\mathcal{X})\) is finite dimensional? Interestingly, he was able to show that there does exist an infinite dimensional closed subalgebra of \(B(\mathcal{X})\) with all but one maximal abelian subalgebras of dimension two. The aim of this note is to give a negative answer to the original question and prove that there does not exist a finite dimensional maximal commutative subalgebra of \(B(\mathcal{X})\) if \(\text{dim} X = \infty\).
Źródło:
Commentationes Mathematicae; 2008, 48, 1
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multipliers of Hardy spaces, quadratic integrals and Foiaş-Williams-Peller operators
Autorzy:
Blower, G.
Powiązania:
https://bibliotekanauki.pl/articles/1217911.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
polynomially bounded operators
Hankel operators
multipliers
Carleson measures
Opis:
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.
Źródło:
Studia Mathematica; 1998, 131, 2; 179-188
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An infinite dimensional Banach algebra with all but one maximal abelian subalgebras of dimension two
Autorzy:
Żelazko, Wiesław
Powiązania:
https://bibliotekanauki.pl/articles/960131.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Abelian algebra
Bounded operators
Complex Banach space
Opis:
I construct a unital closed subalgebra of L(H) with the property announced in the title. Moreover, for any two maxiamal abelian subalgebras of the algebra in question, their intersection consists only of scalar multiples of the unity.
Źródło:
Commentationes Mathematicae; 2008, 48, 1
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On invariant measures for power bounded positive operators
Autorzy:
Sato, Ryotaro
Powiązania:
https://bibliotekanauki.pl/articles/1287342.pdf
Data publikacji:
1996
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
power bounded and Cesàro bounded positive operators
invariant measures
$L_1$ spaces
Opis:
We give a counterexample showing that $\overline{(I-T*)L_{∞}} ∩ L^{+}_{∞} = {0}$ does not imply the existence of a strictly positive function u in $L_1$ with Tu = u, where T is a power bounded positive linear operator on $L_1$ of a σ-finite measure space. This settles a conjecture by Brunel, Horowitz, and Lin.
Źródło:
Studia Mathematica; 1996, 120, 2; 183-189
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On operators with unitary ϱ-dilations
Autorzy:
Ando, T.
Takahashi, K.
Powiązania:
https://bibliotekanauki.pl/articles/1294732.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
polynomially bounded operators
operators of class $C_ϱ$
unitary ϱ-dilation
Opis:
We show a polynomially boundend operator T is similar to a unitary operator if there is a singular unitary operator W and an injection X such that XT = WX. If, in addition, T is of class $C_ϱ$, then T itself is unitary.
Źródło:
Annales Polonici Mathematici; 1997, 66, 1; 11-14
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Volterra integral operators on a family of Dirichlet-Morrey spaces
Autorzy:
Hu, Lian
Liu, Xiaosong
Powiązania:
https://bibliotekanauki.pl/articles/29519523.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Dirichlet-Morrey type space
Carleson measure
Volterra integral operators
bounded operators
essential norm
Opis:
A family of Dirichlet-Morrey spaces $ \mathcal{D}_{\lambda,K} $ of functions analytic in the open unit disk $ \mathbb{D} $ are defined in this paper. We completely characterize the boundedness of the Volterra integral operators $ T_g, I_g $ and the multiplication operator $ M_g $ on the space $ \mathcal{D}_{\lambda,K} $. In addition, the compactness and essential norm of the operators $ T_g $ and $ I_g $ on $ \mathcal{D}_{\lambda,K} $ are also investigated.
Źródło:
Opuscula Mathematica; 2023, 43, 5; 633-649
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Weakly precompact operators on $C_{b}(X,E)$ with the strict topology
Autorzy:
Stochmal, Juliusz
Powiązania:
https://bibliotekanauki.pl/articles/729586.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
spaces of vector-valued continuous functions
strict topologies
operator measures
strongly bounded operators
weakly precompact operators
Opis:
Let X be a completely regular Hausdorff space, E and F be Banach spaces. Let $C_{b}(X,E)$ be the space of all E-valued bounded continuous functions on X, equipped with the strict topology β. We study weakly precompact operators $T:C_{b}(X,E) → F$. In particular, we show that if X is a paracompact k-space and E contains no isomorphic copy of l¹, then every strongly bounded operator $T:C_{b}(X,E) → F$ is weakly precompact.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2016, 36, 1; 65-77
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Putnam-Fuglede property for paranormal and *-paranormal operators
Autorzy:
Pagacz, P.
Powiązania:
https://bibliotekanauki.pl/articles/254725.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
power-bounded operators
paranormal operators
*-paranormal operators
k-paranormal operators
k*-paranormal operators
Putnam-Fuglede theorem
Opis:
An operator T ∈ B(H) is said to have the Putnam-Fuglede commutativity property (PF property for short) if T*X = XJ for any X ∈ B(K,H) and any isometry J ∈ B(K) such that TX = XJ*. The main purpose of this paper is to examine if paranormal operators have the PF property. We prove that k*-paranormal operators have the PF property. Furthermore, we give an example of a paranormal without the PF property.
Źródło:
Opuscula Mathematica; 2013, 33, 3; 565-574
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Order bounded composition operators on the Hardy spaces and the Nevanlinna class
Autorzy:
Jaoua, Nizar
Powiązania:
https://bibliotekanauki.pl/articles/1217094.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
composition operators
order bounded maps
Hardy spaces
Nevanlinna class
radial limit
moment sequences and analytic moment sequences
Opis:
We study the order boundedness of composition operators induced by holomorphic self-maps of the open unit disc D. We consider these operators first on the Hardy spaces $H^p$ 0 < p < ∞ and then on the Nevanlinna class N. Given a non-negative increasing function h on [0,∞[, a composition operator is said to be X,L_h-order bounded (we write (X,L_h)-ob) with $X = H^p$ or X = N if its composition with the map f ↦ f*, where f* denotes the radial limit of f, is order bounded from X into $L_h$. We give a complete characterization and a family of examples in both cases. On the other hand, we show that the ($N,log^{+}L$)-ob composition operators are exactly those which are Hilbert-Schmidt on $H^2$. We also prove that the ($N,L^q$)-ob composition operators are exactly those which are compact from N into $H^q$.
Źródło:
Studia Mathematica; 1999, 134, 1; 35-55
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uniformly bounded Nemytskij operators acting between the Banach spaces of generalized Hölder functions
Autorzy:
Lupa, M.
Wróbel, M.
Powiązania:
https://bibliotekanauki.pl/articles/122593.pdf
Data publikacji:
2017
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
Nemytskij operator
generalized Hölder condition
uniformly bounded mapping
funkcja Holdera
operator Niemyckiego
jednostajnie ograniczone odwzorowanie
jednostajnie ciągłe odwzorowan
Opis:
We investigate the Nemytskij (composition, superposition) operators acting between Banach spaces of r -times differentiable functions defined on the closed intervals of the real line with the r-derivatives satisfying a generalized Hölder condition. The main result says that if such a Nemytskij operator is uniformly bounded (in a special case uniformly continuous) then its generator is an affine function with respect to the second variable, i.e., the Matkowski representation holds. This extends an earlier result where an operator is assumed to be Lipschitzian.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2017, 16, 4; 37-45
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On \(C^{(n)}\)-Almost Periodic Solutions to Some Nonautonomous Differential Equations in Banach Spaces
Autorzy:
Baillon, Jean-Bernard
Blot, Joël
N'Guérékata, Gaston M.
Pennequin, Denis
Powiązania:
https://bibliotekanauki.pl/articles/746570.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
\(C^{(n)}\)-almost periodic function
family of bounded operators
exponentially stable
Acquistapace-Terreni conditions
uniform spectrum of bounded functions
Opis:
In this paper we prove the existence and uniqueness of \(C^{(n)}\)-almost periodic solutions to the nonautonomous ordinary differential equation \(x'(t) = A(t)x(t) + f(t)\), \(t\in\mathbb{R}\), where \(A(t)\) generates an exponentially stable family of operators \((U (t, s))\) \(t\geq s\) and \(f\) is a \(C^{(n)}\)-almost periodic function with values in a Banach space \(X\). We also study a Volterra-like equation with a \(C^{(n)}\)-almost periodic solution.
Źródło:
Commentationes Mathematicae; 2006, 46, 2
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uniformly bounded Nemytskij operators generated by set-valued functions between generalized Hölder function spaces
Autorzy:
Matkowski, Janusz
Wróbel, Małgorzata
Powiązania:
https://bibliotekanauki.pl/articles/729369.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Nemytskij composition operator
uniformly bounded operator
set-valued function
generalized Hölder function metric space
Opis:
We prove that the generator of any uniformly bounded set-valued Nemytskij operator acting between generalized Hölder function metric spaces, with nonempty compact and convex values is an affine function with respect to the function variable.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2011, 31, 2; 183-198
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bounded projections in weighted function spaces in a generalized unit disc
Autorzy:
Karapetyan, A.
Powiązania:
https://bibliotekanauki.pl/articles/1311367.pdf
Data publikacji:
1995
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
generalized unit disc
holomorphic and pluriharmonic functions
weighted spaces
integral representations
bounded integral operators
Opis:
Let $M_{m,n}$ be the space of all complex m × n matrices. The generalized unit disc in $M_{m,n}$ is $R_{m,n} = {Z ∈ M_{m,n}: I^{(m)} - ZZ^\ast \text{ is positive definite} }$. Here $I^{(m)} ∈ M_{m,m}$ is the unit matrix. If 1 ≤ p < ∞ and α > -1, then $L_{α}^{p}(R_{m,n})$ is defined to be the space $L^p{R_{m,n}; [det(I^{(m)} - ZZ^\ast)]^α dμ_{m,n}(Z)}$, where $μ_{m,n}$ is the Lebesgue measure in $M_{m,n}$, and $H_α^p(R_{m,n}) ⊂ L_{α}^{p}(R_{m,n})$ is the subspace of holomorphic functions. In [8,9] M. M. Djrbashian and A. H. Karapetyan proved that, if $Reβ > (α+1)//p -1$ (for 1 < p < ∞) and Re β ≥ α (for p = 1), then $f(\mathcal{Z})= T_{m,n}^{β}(f)(\mathcal{Z}), \mathcal{Z} ∈ R_{m,n},$ where $T_{m,n}^{β}$ is the integral operator defined by (0.13)-(0.14). In the present paper, given 1 ≤ p < ∞, we find conditions on α and β for $T_{m,n}^{β}$ to be a bounded projection of $L_α^p(R_{m,n})$ onto $H_α^p(R_{m,n})$. Some applications of this result are given.
Źródło:
Annales Polonici Mathematici; 1995, 62, 3; 193-218
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 45

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies