Derivations on generalized semidirect products of Banach algebras

Autor: Hasan Pourmahmood Aghababa
Rok vydání: 2016
Předmět:
Zdroj: Banach J. Math. Anal. 10, no. 3 (2016), 509-522
ISSN: 1735-8787
DOI: 10.1215/17358787-3607156
Popis: Let $A$ and $B$ be Banach algebras, let $\theta:A\to B$ be a continuous Banach algebra homomorphism, and let $I$ be a closed ideal in $B$ . Then the $l^{1}$ -direct sum of $A$ and $I$ with a special product becomes a Banach algebra, denoted by $A\bowtie^{\theta}I$ , which we call the generalized semidirect product of $A$ and $I$ . In this article, among other things, we first characterize derivations on $A\bowtie^{\theta}I$ and then we compute the first cohomology group of $A\bowtie^{\theta}I$ when the first cohomology groups of $A$ with coefficients in $A$ and $I$ are trivial. As an application we characterize the first cohomology group of second duals of dual Banach algebras. Then we provide a nice characterization of the first cohomology group of $A\bowtie^{\mathrm{id}}A$ . Furthermore, we calculate the first cohomology group of some concrete Banach algebras related to locally compact groups.
Databáze: OpenAIRE