'This volume dwells on three advanced and useful approaches to nonrelativistic quantum theory: the WKB method in exact form, phase-space quantization (Weyl--Wigner, Husimi), and path integrals. A majority of the covered topics are ignored by mainstream textbooks, making this text quite innovative. The exposition is comprehensive and pedagogically oriented, with numerous concrete examples detailed. This will prove a valuable textbook for academics and students aiming beyond basic quantum theory, to make them fluent and assist their teaching in several areas that actively serve in current research.' André Voros, Institut de Physique Théorique, CEA-Saclay, France
Preface; 1. Propagator and resolvent; 2. The WKB method and non-perturbative effects; 3. The phase space formulation of quantum mechanics; 4. The path integral formulation of quantum mechanics; 5. Metastable states; Appendix A: Asymptotic series and Borel resummation; Appendix B: Special functions; Appendix C: Gaussian integration; References; Index.