The Principles of Quantum MechanicsThe first edition of this work appeared in 1930, and its originality won it immediate recognition as a classic of modern physical theory. The fourth edition has been bought out to meet a continued demand. Some improvements have been made, the main one being the complete rewriting of thechapter on quantum electrodymanics, to bring in electronpair creation. This makes it suitable as an introduction to recent works on quantum field theories. 
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LibraryThing Review
User Review  yapete  LibraryThingThe classic on the formalism of quantum mechanics. Only for the serious... But if you understand this stuff, this is one of the most clear and lucid books on QM ever written. Read full review
LibraryThing Review
User Review  agricolaoval  LibraryThingDirac had a knack of explaining quite complicated things in a simple and understandable way. This is of course an old book, and it is very elementary, but I still remember the joyful feeling of being ... Read full review
Contents
THE PRINCIPLE OF SUPERPOSITION  1 
The Polarization of Photons  4 
Interference of Photons  7 
Superposition and Indeterminacy  10 
Mathematical Formulation of the Principle  14 
Bra and Ket Vectors  18 
DYNAMICAL VARIABLES AND OBSERVABLES  23 
Conjugate Relations  26 
The Change in the Energylevels caused by a Perturbation  168 
The Perturbation considered as causing Transitions  172 
Application to Radiation  175 
Transitions caused by a Perturbation Independent of the Time  178 
The Anomalous Zeeman Effect  181 
COLLISION PROBLEMS  185 
The Scattering Coefficient  188 
Solution with the Momentum Representation  193 
Eigenvalues and Eigenvectors  29 
Observables  34 
Functions of Observables  41 
The General Physical Interpretation  45 
Commutability and Compatibility  49 
REPRESENTATIONS  53 
The 8 Function  58 
Properties of the Basic Vectors  62 
The Representation of Linear Operators  67 
Probability Amplitudes  72 
Theorems about Functions of Observables  76 
Developments in Notation  79 
THE QUANTUM CONDITIONS  84 
Schrddingers Representation  89 
The Momentum Representation  94 
Heisenbergs Principle of Uncertainty  97 
Displacement Operators  99 
Unitary Transformations  103 
THE EQUATIONS OF MOTION  108 
Heisenbergs Form for the EVuations of Motion  111 
Stationary States  116 
The Free Particle  118 
The Motion of Wave Packets  121 
The Action Principle  126 
The Gibbs Ensemble  130 
ELEMENTARY APPLICATIONS  136 
Angular Momentum  140 
Properties of Angular Momentum  144 
The Spin of the Electron  149 
Motion in a Central Field of Force  152 
Energylevels of the Hydrogen Atom  156 
Selection Rules  159 
The Zeeman Effect for the Hydrogen Atom  165 
PERTURBATION THEORY  167 
Dispersive Scattering  199 
Resonance Scattering  201 
Emission and Absorption  204 
SYSTEMS CONTAINING SEVERAL SIMILAR PARTICLES  207 
Permutations as Dynamical Variables  211 
Permutations as Constants of the Motion  213 
Determination of the Energylevels  216 
Application to Electrons  219 
THEORY OF RADIATION  225 
The Connexion between Bosons and Oscillators  227 
Emission and Absorption of Bosons  232 
Application to Photons  235 
The Interaction Energy between Photons and an Atom  239 
Emission Absorption and Scattering of Radiation  244 
An Assembly of Fermions  248 
RELATIVISTIC THEORY OF THE ELECTRON  253 
The Wave Equation for the Electron  254 
Invariance under a Lorentz Transformation  258 
The Motion of a Free Electron  261 
Existence of the Spin  263 
Transition to Polar Variables  267 
The Finestructure of the Energylevels of Hydrogen  269 
Theory of the Positron  273 
QUANTUM ELECTRODYNAMICS  276 
Relativistic Form of the Quantum Conditions  280 
The Dynamical Variables at one Time  283 
The Supplementary Conditions  287 
Electrons and Positrons by Themselves  292 
The Interaction  298 
The Physical Variables  302 
Interpretation  306 
Applications  310 
313  
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Common terms and phrases
absorption algebraic angular momentum anticommutation applied arbitrary atom basic bras basic kets basic vectors belonging bosons canonical coordinates classical mechanics classical theory coefficient commutation relations commuting observables complete set components conjugate complex conjugate imaginary constant coordinates and momenta defined denote diagonal displacement dynamical system dynamical variables eigen eigenbras eigenstate eigenvalues electron emission energylevels equal equations of motion expressed fermions field form a complete formula given gives Hamiltonian Heisenberg picture hence independent infinity integral interaction ket vector linear operator mathematical matrix elements multiplied obtain orthogonal oscillator permutation photon physical polarization positrons probability quantities quantum mechanics quantum theory radiation real dynamical variable relativistic representation representative result righthand side satisfy scalar product scattering Schrodinger Schrodinger's set of commuting simultaneous eigenkets solution spin standard ket stationary superposition supplementary conditions symmetrical theorem tion transition unitary transformation unperturbed system vanish velocity wave equation wave function zero