The Bohr compactification of divisible subsemigroups of a cylinder (Q2710564)

A semigroup \(S\) of the cylinder \(\mathbb R\times G\), where \(G\) is a Lie group, is called an \(A\)-semigroup if it satisfies the following conditions: (1) \(S\) is exponential; (2) \(S\) is invariant; (3) \(S\) is reduced, i.e. its interior in \(\mathbb R\times G\) is non-empty and it does contain any normal non-trivial subgroup of \(\mathbb R\times G\); (4) \(S\cap (\{0\}\times G)=\{(0,1_G)\}\). Structure \(A\)-semigroups and their Bohr compactification are studied.