“…Since the information geometrical structure for probability distributions plays important roles in several topics in information theory as well as statistics, it is better to describe the information geometry of transition matrices so that it can be easily applied to these topics. In fact, the authors applied it to finite-length evaluations of the tail probability, the error probability in simple hypothesis testing, source coding, channel coding, and random number generation in Markov chain as well as the estimation error of parametric family of transition matrices [17,18]. Thus, we revisit the exponential family of transition matrices [2,5] in a manner consistent with the above purpose by using Bregmann divergence [21,20].…”