Central idempotent measures on connected locally compact groups

AbstractA measure μ of finite total variation on a locally compact group G is idempotent if μ ∗ μ = μ, and is central if invariant under all inner automorphisms of G. Recent results of D. Rider and D. Ragozin concerning compact groups are combined with results of the authors for noncompact groups to determine all central idempotent measures on a connected G in terms of the structural features of G