NECESSARY AND SUFFICIENT CONDITIONS FOR A BOUNDED SOLUTION TO THE OPTIMALITY EQUATION IN AVERAGE REWARD MARKOV DECISION CHAINS

We consider average reward Markov decision processes with discrete time parameter and denumerable state space. We are concerned with the following problem: find necessary and sufficient conditions so that, for arbitrary bounded reward function, the corresponding average reward optimality equation has a bounded solution. This problem is solved for a class of systems including the case in which, under the action of any stationary policy, the state space is an irreducible positive recurrent class.