Quantum Mechanics (Symmetries) deals with a particularly appealing and successful concept in advanced quantum mechanics. After a brief introduction to symmetries in classical mechanics, the text turns to their relevance in quantum mechanics, the consequences of rotation symmetry, and the general theory of Lie groups. The isospin group, hypercharge, SU(3) and their applications are all dealt with in depth before chapters on charm, SU(4), and dynamical symmetries lead to the frontiers of research in particle physics. This unique text comprises more than 120 detailed, worked examples and problems.As the third reprint of the second edition, this book has been revised to bring the text up to date. TOC:Symmetries in Quantum Mechanics.- Angular Momentum Algebra Representation of Angular Momentum - Generators of SO(3).- Mathematical Supplement: Fundamental Properties of Lie Groups.- Symmetry Groups and Their Physical Meaning - General Considerations.- The Isospin Group (Isobaric Spin).- The Hypercharge.- The SU(3) Symmetry.- Quarks and SU(3).- Representaions of the Permutation Group and Young Tableaux.- Mathematical Excursion. Group Characters.- Charm and SU(4).- Mathematical Supplement.- Special Discrete Symmetries.- Dynamical Symmetries.- Mathematical Exursion: Non-compact Lie Groups.- Subject Index.