Generalized notion of amenability for a class of matrix algebras
  We investigate the notions of amenability and its related homological notions for a class of $I\times I$-upper triangular matrix algebra, say $UP(I,A)$, where $A$ is a Banach algebra equipped with a non-zero 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 the notions of pseudo-amenability and approximate biprojectivity of $UP(I,A)$. 
Amir Sahami
math.FA