  We study actions by higher-rank abelian groups on quotients of semisimple Lie
groups with finite center. First, we consider actions arising from the flows of
two commuting elements of the Lie algebra--one nilpotent, and the other
semisimple. Second, we consider actions from two commuting unipotent flows
coming from two commuting embedded copies of SL(2,R). In both cases we show
that any smooth real-valued cocycle over the action is cohomologous to a
constant cocycle via a smooth transfer function.
