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Functional calculus in weighted group algebras.

Jacek Dziubanski, Jean Ludwig, Carine Molitor-Braun (2004)

Revista Matemática Complutense

Let G be a compactly generated, locally compact group with polynomial growth and let ω be a weight on G. We look for general conditions on the weight which allow us to develop a functional calculus on a total part of L1(G,ω). This functional calculus is then used to study harmonic analysis properties of L1(G,ω), such as the Wiener property and Domar's theorem.

Functionals on Banach Algebras with Scattered Spectra

H. S. Mustafayev (2004)

Bulletin of the Polish Academy of Sciences. Mathematics

Let A be a complex, commutative Banach algebra and let M A be the structure space of A. Assume that there exists a continuous homomorphism h:L¹(G) → A with dense range, where L¹(G) is a group algebra of the locally compact abelian group G. The main results of this note can be summarized as follows: (a) If every weakly almost periodic functional on A with compact spectra is almost periodic, then the space M A is scattered (i.e., M A has no nonempty perfect subset). (b) Weakly almost periodic functionals...

Generalization of the weak amenability on various Banach algebras

Madjid Eshaghi Gordji, Ali Jabbari, Abasalt Bodaghi (2019)

Mathematica Bohemica

The generalized notion of weak amenability, namely ( ϕ , ψ ) -weak amenability, where ϕ , ψ are continuous homomorphisms on a Banach algebra 𝒜 , was introduced by Bodaghi, Eshaghi Gordji and Medghalchi (2009). In this paper, the ( ϕ , ψ ) -weak amenability on the measure algebra M ( G ) , the group algebra L 1 ( G ) and the Segal algebra S 1 ( G ) , where G is a locally compact group, are studied. As a typical example, the ( ϕ , ψ ) -weak amenability of a special semigroup algebra is shown as well.

Generalized notions of amenability for a class of matrix algebras

Amir Sahami (2019)

Commentationes Mathematicae Universitatis Carolinae

We investigate the amenability and its related homological notions for a class of I × I -upper triangular matrix algebra, say UP ( I , A ) , where A is a Banach algebra equipped with a nonzero character. We show that UP ( I , A ) is pseudo-contractible (amenable) if and only if I is singleton and A is pseudo-contractible (amenable), respectively. We also study pseudo-amenability and approximate biprojectivity of UP ( I , A ) .

Good weights for weighted convolution algebras

Sandy Grabiner (2010)

Banach Center Publications

Weighted convolution algebras L¹(ω) on R⁺ = [0,∞) have been studied for many years. At first results were proved for continuous weights; and then it was shown that all such results would also hold for properly normalized right continuous weights. For measurable weights, it was shown that one could construct a properly normalized right continuous weight ω' with L¹(ω') = L¹(ω) with an equivalent norm. Thus all algebraic and norm-topology results remained true for measurable weights. We now show that,...

Harmonic analysis of spherical functions on S U ( 1 , 1 )

Y. Benyamini, Yitzhak Weit (1992)

Annales de l'institut Fourier

Denote by L 1 ( K G / K ) the algebra of spherical integrable functions on S U ( 1 , 1 ) , with convolution as multiplication. This is a commutative semi-simple algebra, and we use its Gelfand transform to study the ideals in L 1 ( K G / K ) . In particular, we are interested in conditions on an ideal that ensure that it is all of L 1 ( K G / K ) , or that it is L 0 1 ( K G / K ) . Spherical functions on S U ( 1 , 1 ) are naturally represented as radial functions on the unit disk D in the complex plane. Using this representation, these results are applied to characterize harmonic...

Homology and cohomology of Rees semigroup algebras

Frédéric Gourdeau, Niels Grønbæk, Michael C. White (2011)

Studia Mathematica

Let S be a Rees semigroup, and let ℓ¹(S) be its convolution semigroup algebra. Using Morita equivalence we show that bounded Hochschild homology and cohomology of ℓ¹(S) are isomorphic to those of the underlying discrete group algebra.

Currently displaying 61 – 80 of 191