Operator semigroups for which reducibility implies decomposability
Livshits, L.MacDonald, Gordon W.Mathes, B.Radjavi, H.
Mathematics and Statistics
A description of the lattice of invariant subspaces is provided for multiplicative semigroups S of bounded operators on L-p(X, mu) which are closed under multiplication on the left or right by bounded multiplication operators. Applications are then given to semigroups of positive quasinilpotent operators.