Locally compact subgroups of the spectrum of the measure algebra III

The maximal ideal space of the measure algebra of a locally compact abelian (LCA) group has the structure of a compact commutative semitopological semigroup (separately continuous multiplication). Idempotents in the semigroup correspond to certain algebraic projections on the measure algebra. In this paper we study the maximal groups about certain idempotents. This research was partially supported by NSF contract number GP-19852 and GP-31483X.