The Wigner-Weyl formalism and the semi-classical relativistic approximation
arXiv:hep-th/9307135
Abstract
The relativistic semi-classical approximation for a free massive particle is studied using the Wigner-Weyl formalism. A non-covariant Wigner function is proposed using the Newton-Wigner position operator. The perturbative solution for the time evolution is found. Causality is found to be perturbatively respected.
6 pages