Perturbative Methods in Field Theory
- 356 Downloads
In the preceding chapters, we have described several physical systems, photons, phonons, electron gas, nuclei, which we have treated by using semiquantitative methods: orders of magnitude, models, variational methods. The object of Chaps. 9 and 10 is to develop a more systematic method for calculating the effects of the interactions: the perturbation method. One finds that all the perturbative calculations used in field theory and in many-body problems proceed from the same common core, the time-dependent perturbative methods of quantum mechanics. At a strictly formal level, the method presents a large degree of generality. One must nevertheless take care not to abuse this apparent generality. While the basic formalism is unique, the applications are as diverse as the physical situations being considered. Thus, before beginning any significant perturbative calculation, it is necessary to consider the prerequisites of the physical effects and their orders of magnitude. The art of such a calculation resides in the judicious handling of a well-posed physical question. Before undertaking calculations, it is important to first determine the physical relevance of the expected results.
KeywordsGreen Function Feynman Diagram Perturbative Expansion Normal Order Perturbation Series
Unable to display preview. Download preview PDF.
Elementary Particles, Photons and Electrons
- W. E. Thirring, Principles of quantum electrodynamics, Academic Press, 1958.Google Scholar
- R. P. Feynman, Quantum electrodynamics, Benjamin, 1962.Google Scholar
- R. Omnes, Introduction to particle physics, Interscience, 1971.Google Scholar
- J. M. Jauch, F. Rohrlich, The theory of photons and electrons (2nd edition), Springer, 1980.Google Scholar
- T. D. Lee, Particle physics and introduction to field theory, Harwood Academic Publishers, 1981.Google Scholar
- T. P. Cheng, L. F. Li, Gauge theory of elementary particle physics, Clarendon Press, 1984.Google Scholar
- B. De Wit, J. Smith, Field theory in particle physics, North-Holland, 1986.Google Scholar
- B. R. Martin, G. Shaw, Particle physics, Wiley, 1992.Google Scholar