Author: P. A. M. Dirac
The Principles of Quantum Mechanics (Fourth Edition) by P. A. M. Dirac is a foundational and highly influential textbook in theoretical physics. First published in 1930, with the fourth edition released in 1958, it presents quantum mechanics in a formal, axiomatic framework. Dirac introduces key concepts such as superposition, operators, and the Dirac notation (bra-ket), which became standard in quantum theory. The book emphasizes mathematical rigor and logical structure over experimental detail. Topics include the quantum mechanics of systems, perturbation theory, identical particles, quantum electrodynamics, and the relativistic theory of the electron. The fourth edition notably updates the treatment of electron-positron theory and quantum field aspects. Known for its depth and elegance, this book is best suited for advanced students and researchers. It remains a classic reference for the conceptual foundations of quantum mechanics.