Adam Bobrowski is a professor and Chairman of the Department of Mathematics at Lublin University of Technology, Poland. He is a pure mathematician who uses the language of operator semigroups to describe stochastic processes. He has authored and co-authored nearly 70 papers on the subject, and five books, including Functional Analysis for Probability and Stochastic Processes (2005) and Convergence of One-Parameter Operator Semigroups (2016).

• A non-technical introduction; 1. A guided tour through the land of operator semigroups; 2. Generators versus intensity matrices; 3. Boundary theory: core results; 4. Boundary theory continued; 5. The dual perspective; Solutions and hints to selected exercises; Commonly used notations; References; Index.

'Western science is largely based on deducing global properties of systems from the local ones, and differential equations have proved to be a successful mathematical tool for it. It has been realized, however, that even in linear systems there can occur phase transitions that cannot be deduced from the underlying equations. Originally observed in Markov processes, the theory of phase transitions has been recently extended to general master equations. This monograph, building upon Feller's concept of the process boundary and linking it in a novel way with functional analytic tools, provides a refined analysis of the evolution beyond the phase transition. It offers a unique blend of probability and functional analysis addressing a topical problem of nonlocal and emerging properties of infinite-dimensional linear systems and largely extending the existing results.' Jacek Banasiak, University of Pretoria