This paper establishes a rather complete optimality theory for the average cost semi-Markov decision model with a denumerable state space, compact metric action sets and unbounded one-step costs for the case where the underlying Markov chains have a single ergotic set. Under a condition which,...

Recent papers have shown that [Pi][infinity]k = 1 P(k) = limm--[infinity] (P(m) ... P(1)) exists whenever the sequence of stochastic matrices {P(k)}[infinity]k = 1 exhibits convergence to an aperiodic matrix P with a single subchain (closed, irreducible set of states). We show how the limit...