Large deviations for empirical measures of not necessarily irreducible countable Markov chains with arbitrary initial measures

All known results on large deviations of occupation measures of Markov processes are based on the assumption of (essential) irreducibility. In this paper we establish the weak* large deviation principle of occupation measures for any countable Markov chain with arbitrary initial measures. The new rate function that we obtain is not convex and depends on the initial measure, contrary to the (essentially) irreducible case.