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: 10

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

Wyniki wyszukiwania

help Sortuj według:

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

Transitivity for linear operators on a Banach space

100%
Yood B.
Studia Mathematica
|
1999
|
tom 132
|
nr 3
239-243
EN
Let G be the multiplicative group of invertible elements of E(X), the algebra of all bounded linear operators on a Banach space X. In 1945 Mackey showed that if $x_1,…,x_n$ and $y_1,…,y_n$ are any two sets of linearly independent elements of X with the same number of items, then there exists T ∈ G so that $T(x_k) = y_k$, $k = 1,…,n$. We prove that some proper multiplicative subgroups of G have this property.
2
Content available remote

Finite-dimensional ideals in Banach algebras

100%
Yood B.
Colloquium Mathematicum
|
1992
|
tom 63
|
nr 2
295-301
3
Content available remote

On the non-existence of norms for some algebras of functions

100%
Yood B.
Studia Mathematica
|
1994
|
tom 111
|
nr 1
97-101
EN
Let C(Ω) be the algebra of all complex-valued continuous functions on a topological space Ω where C(Ω) contains unbounded functions. First it is shown that C(Ω) cannot have a Banach algebra norm. Then it is shown that, for certain Ω, C(Ω) cannot possess an (incomplete) normed algebra norm. In particular, this is so for $Ω = ℝ^n$ where ℝ is the reals.
4
Content available remote

Centralizers for subsets of normed algebras

100%
Yood B.
Studia Mathematica
|
2000
|
tom 142
|
nr 1
1-6
EN
Let G be the set of invertible elements of a normed algebra A with an identity. For some but not all subsets H of G we have the following dichotomy. For x ∈ A either $cxc^{-1} = x$ for all c ∈ H or $sup {∥cxc^{-1}∥ : c ∈ H} = ∞ $. In that case the set of x ∈ A for which the sup is finite is the centralizer of H.
5
Content available remote

C*-seminorms

100%
Yood B.
Studia Mathematica
|
1996
|
tom 118
|
nr 1
19-26
EN
A necessary and sufficient condition is given for a*-algebra with identity to have a unique maximal C*-seminorm. This generalizes the result, due to Bonsall, that a Banach *-algebra with identity has such a*-seminorm.
6
Content available remote

Commutators in Banach *-algebras

100%
Yood B.
Studia Mathematica
|
2008
|
tom 186
|
nr 1
1-10
EN
The set of commutators in a Banach *-algebra A, with continuous involution, is examined. Applications are made to the case where A = B(ℓ₂), the algebra of all bounded linear operators on ℓ₂.
7
Content available remote

Commutativity theorems for normed *-algebras

100%
Yood B.
Colloquium Mathematicum
|
1996
|
tom 69
|
nr 1
75-80
8
Content available remote

Ascent, descent and roots of Fredholm operators

100%
Yood B.
Studia Mathematica
|
2003
|
tom 158
|
nr 3
219-226
EN
Let T be a Fredholm operator on a Banach space. Say T is rootless if there is no bounded linear operator S and no positive integer m ≥ 2 such that $S^{m} = T$. Criteria and examples of rootlessness are given. This leads to a study of ascent and descent whether finite or infinite for T with examples having infinite ascent and descent.
9
Content available remote

Incomplete normed algebra norms on Banach algebras

45%
Tomiuk B. J., Yood B.
Studia Mathematica
|
1989-1990
|
tom 95
|
nr 2
119-132
10
Content available remote

Continuity for linear maps on Banach algebras

32%
Yood B.
Studia Mathematica
|
1968
|
tom 31
|
nr 3
263-266
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.