2008/04/28 by Liuer Ye, Ye, Liuer, Xianping Guo +3 · 1 citation
Mathematics · #60J27 #60J35 #60J75 #FOS: Mathematics #Probability (math.PR) #math.PR #msc:60J27 #msc:60J35 #msc:60J75
paper · pdf · doi:10.48550/arxiv.0804.4441
22 pages
arxiv created 2008/04/28 · arxiv updated 2009/12/01
This paper is about the existence and regularity of the transition probability matrix of a nonhomogeneous continuous-time Markov process with a countable state space. A standard approach to prove the existence of such a transition matrix is to begin with a continuous (in t) and conservative matrix Q(t)=[qij(t)] of nonhomogeneous transition rates qij(t), and use it to construct the transition probability matrix. Here we obtain the same result except that the qij(t) are only required to satisfy a mild measurability condition, and Q(t) may not be conservative. Moreover, the resulting transition matrix is shown to be the minimum transition matrix and, in addition, a necessary and sufficient condition for it to be regular is obtained. These results are crucial in some applications of nonhomogeneous continuous-time Markov processes, such as stochastic optimal control problems and stochastic games, which motivated this work in the first place.