Regularity of semigroup rings
Julian Weissglass · Proceedings of the American Mathematical Society · 1970
The conditions under which a semigroup ring is regular (in the sense of von Neumann) are investigated. Sufficient conditions are obtained in order that the semigroup ring of an inverse semigroup be regular. Consequences of the regularity of the semigroup ring for the subgroups of the semigroup are established. The two results are then used to find necessary and sufficient conditions for the regularity of the semigroup ring when the semigroup is inverse and a union of groups.