Biflatness of certain semigroup algebras

Abstract

In the present paper, we consider biflatness of certain classes of semigroup<br /><br />algebras. Indeed, we give a necessary condition for a band semigroup algebra to be<br /><br />biflat and show that this condition is not sufficient. Also, for a certain class of inverse<br /><br />semigroups S, we show that the biflatness of ell^{1}(S)^{primeprime} is <br /><br />equivalent to the biprojectivity of ell^{1}(S).