QUANTUM TRANSPORT-THEORY BASED ON THE EQUILIBRIUM DENSITY PROJECTION TECHNIQUE

We introduce a projection technique, called the equilibrium density pr ojection technique, which involves two schemes: the ensemble average p rojection scheme and the combined projection scheme. Using this techni que directly on the Liouville equation, we derive the linear-nonlinear response formula. We also expand the scattering factors to a continue d-fraction representation to avoid the danger of divergence, and expan d again the continued-fraction representation formula in a series form . Finally, we introduce a simple example for the linear response term and compare the two schemes.