Reduced and Extended Weak Coupling Limit
arXiv:0704.0669
Abstract
We give an extended review of recent work on the extended weak coupling limit. Background material on completely positive semigroups and their unitary dilations is given, as well as a particularly easy construction of `quadratic noises'.
39 pages, review article for the conference "Noncommutative harmonic analysis" in Bedlewo, Poland, 2006. v1-->v2, corrections in Section 5 and changes in notation