The moyal representation for spin: Joseph C. Várilly and José M. Gracia-Bondía. Escuela de Matemática, Universidad de Costa Rica, San José, Costa Rica
- Publisher
- Elsevier Science
- Year
- 1989
- Tongue
- English
- Weight
- 56 KB
- Volume
- 189
- Category
- Article
- ISSN
- 0003-4916
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✦ Synopsis
The phase-space approach to spin is developed from two basic principles, SCI(Z)-covariance and traciality, as a theory of Wigner functions on the sphere. The twisted product of phase-space functions is related to group convolution on SLr(2) by means of a Fourier transform theory on the coadjoint orbits, which yields the Plancberel-Parseval formula. Coherent spin states provide an alternative route to the same phase-space description of spin. The Wigner functions for spin states and transitions are exhibited up to j=2. It is shown that for Hamiltonians such as arise from time-dependent magnetic fields, the quantum spin dynamics is given entirely by the classical motion on the sphere. The Majorana formula becomes transparent in the Moyal representation.
Consistent
Equations for Interacting Massless Fields of All Spins in the First Order in Curvatures.