An Invitation to Unbounded Representations of ∗-Algebras on Hilbert Space

“This is a fantastic book. The material it covers is wonderful and exciting. The book is well-written, and in fact pleasant to read. It takes a familiar subject --- that is unfortunately not as popular among mathematicians as it should be --- and presents it from a very evocative perspective. Kudos to Schmüdgen.” (Michael Berg, MAA Reviews, July 22, 2023)

“It is very well written, the style is pleasant and attractive, and the information can be used by beginners and by specialists as well. All chapters are accompanied by exercises and pertinent historical comments. … all researchers interested in representation theory may regard this work not only as a reference book but also as a source of inspiration for further development.” (Florian-Horia Vasilescu, zbMATH 1458.47002, 2021)