On Johnson pseudo-contractibility of some semigroup algebras

In this paper we characterize the Johnson pseudo-contractibility of 1(S), where S is a uni-formly locally nite inverse semigroup. We show that for a Brandt semigroup S = M0(G; I) over a non- empty set I, 1(S) is Johnson pseudo-contractible if and only if G is amenable and I is nite. We give some examples to show the di erence between Johnson pseudo-contractibility, pseudo-amenability and pseudo- contractibility among the semigroup algebras.

Keywords:

atness , -biprojectivity , -amenability , -inner amenablility