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Nine years has passed since the 1992 second edition of the encyclopedia was published. This completely revised third edition, which is a university and professional level compendium of chemistry, molecular biology, mathematics, and engineering, is refreshed with numerous articles about current research in these fields. For example, the new edition has an increased emphasis on information processing and biotechnology, reflecting the rapid growth of these areas. The continuing Editor-in-Chief, Robert Meyers, and the Board prepared a new topical outline of physical science and technology to define complete coverage. Section editors are either Nobel Laureates or editors of key journals in their fields. Additional Board members representing the global scientific community were also recruited.
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Encyclopedia of Physical Science and Technology
EN005D-207
June 15, 2001
20:26
Electrodynamics, Quantum W. P. Healy RMIT University
I. Introduction II. Nonrelativistic Quantum Electrodynamics III. Relativistic Quantum Electrodynamics
GLOSSARY Anomalous magnetic moment Difference between the intrinsic magnetic moment of a charged spin- 12 particle and that predicted by the single-particle Dirac theory. Coherent state State of the quantized radiation field in which the average electric and magnetic fields and the average energy are the same as the corresponding quantities for a state of the classical electromagnetic field. C, P, and T symmetries Invariance of quantum electrodynamics under the operations of charge conjugation (or matter–antimatter interchange), parity (or left–right interchange), and time reversal, respectively. Dirac equation Four-component relativistic quantum mechanical wave equation for a spin- 12 particle. Einstein’s A and B coefficients Factors de