From reversible quantum microdynamics to irreversible quantum transport
Abstract
The transition from reversible microdynamics to irreversible transport can be studied very efficiently and systematically with the help of the socalled projection method. After a concise introduction to that method we illustrate its power by using it to analyze the wellknown rate and quantum Boltzmann equations, and we present, as a new application, the derivation of a source term which accounts for the spontaneous creation of electronpositron pairs in strong fields. Thereby we emphasize the pivotal role of time scales: Only if the various time scales exhibited by the dynamics are widely disparate can the evolution of the slower degrees of freedom be described by a conventional Markovian transport equation; otherwise one must account for finite memory effects. We show how the projection method can be employed to determine these time scales and how  if necessary  it allows one to include memory effects in a straightforward manner. There is also an appendix in which we discuss the concepts of entropy and macroscopic irreversibility.
 Publication:

Physics Reports
 Pub Date:
 July 1996
 DOI:
 10.1016/03701573(95)000771
 arXiv:
 arXiv:nuclth/9505009
 Bibcode:
 1996PhR...272....1R
 Keywords:

 Condensed Matter;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory;
 Nuclear Theory
 EPrint:
 Review article, 78 pages, uuencoded compressed PostScript file