The book presents new methods of asymptotic analysis for nonlinearly perturbed semi-Markov processes with a finite phase space. These methods are based on special time-space screening procedures for sequential phase space reduction of semi-Markov processes combined with the systematical use of operational calculus for Laurent asymptotic expansions. Effective recurrent algorithms are composed for getting asymptotic expansions, without and with explicit upper bounds for remainders, for power moments of hitting times, stationary and conditional quasi-stationary distributions for nonlinearly perturbed semi-Markov processes. These results are illustrated by asymptotic expansions for birth-death-type semi-Markov processes, which play an important role in various applications. The book will be a useful contribution to the continuing intensive studies in the area. It is an essential reference for theoretical and applied researchersin the field of stochastic processes and their applications that will contribute to continuing extensive studies in the area and remain relevant for years to come.
"This book is aimed at studying asymptotic expansions for moment hitting times, stationary and conditional quasi-stationary distributions, and various further functionals, for nonlinearly perturbed semi-Markov processes having finite phase space. ... The bibliography is broad and relevant, and includes various publications of the authors thanks to their wide expertise on the topics under investigation. ... book is of interest to researchers working on semi-Markov processes, and provides a useful reference for investigations dealing with asymptotic problems for perturbed stochastic processes." (Antonio Di Crescenzo, Mathematical Reviews, July, 2018)