摘要
The author presents some straightforward proofs for two comparison theorems for Green functions of Markov chains, which slightly improve the previous results by Varopoulos, Durrett and Yan and Chen. A recent result by Rogers and Williams about instantaneous Markov chains is also improved by using the same idea.
The author presents some straightforward proofs for two comparison theorems for Green functions of Markov chains, which slightly improve the previous results by Varopoulos[6, 7],Durrett[3] and Yan and Chen [10]. A recent result by Rogers and Williams[7] about instantaneous Markov chains is also improved by using the same idea.
