Characterization of homological properties of θ-Lau product of Banach algebras


Morteza Essmaili, Ali Rejali, Azam Salehi Marzijarani




Let A and B be two Banach algebras and θ ∈ σ(B). In this paper, we investigate biprojectivity and biflatness of θ-Lau product of Banach algebras A × θ B. Indeed, we show that A × θ B is biprojective if and only if A is contractible and B is biprojective. This generalizes some known results. Moreover, we characterize biflatness of θ-Lau product of Banach algebras under some conditions. As an application, we give an example of biflat Banach algebras A and X such that the generalized module extension Banach algebra X A is not biflat. Finally, we characterize pseudo-contractibility of θ-Lau product of Banach algebras and give an affirmative answer to an open question.