Commutation Relations, Normal Ordering, and Stirling Numbers

This book provides an introduction to the combinatorial aspects of normal ordering in the Weyl algebra and some of its close relatives. It discusses the Stirling numbers, closely related generalizations, and their role as normal ordering coefficients in the Weyl algebra. In addition to the combinatorial aspects, the book presents the relation to operational calculus and describes the physical motivation for ordering words in the Weyl algebra arising from quantum theory, along with some applications.