The text begins with a thorough description of the origins of quantum physics before discussing the mathematical tools required in the field and the postulates upon which it is founded. Quantum Mechanics: Concepts and Applications is broad in scope, covering such aspects as one-dimensional and three- dimensional potentials, angular momentum, rotations and addition of angular momenta, identical particles, time-independent and -dependent approximation methods, scattering theory, relativistic quantum mechanics, and classical field theory among others. Each of these diverse areas are enhanced with a rich collection of illustrative examples and fully-solved problems to ensure complete understanding of this complex topic. Readers of the third edition of Quantum Mechanics: Concepts and Applications will also find: * Two new chapters -- one dealing with relativistic quantum mechanics and the other with the Lagrangian derivations of the Klein-Gordon and Dirac equations -- and three new appendices to support them * About 90 solved examples integrated throughout the text that are intended to illustrate individual concepts within a broader topic * About 200 fully-solved, multi-step problems at the end of each chapter that integrate multiple concepts introduced throughout the chapter * More than 400 unsolved exercises that may be used to practice the ideas presented A Solutions Manual is available only to those instructors adopting the book, on request, offering detailed solutions to all exercises. Quantum Mechanics: Concepts and Applications is a comprehensive textbook which is most useful to senior undergraduate and first-year graduate students seeking mastery of the field, as well as to researchers in need of a quick, practical reference for the various techniques necessary for optimal performance in the subject.