Wick theorem for all orderings of canonical operators

Lajos Diósi
2018 Journal of Physics A: Mathematical and Theoretical  
Wick's theorem, known for yielding normal ordered from time-ordered bosonic fields may be generalized for a simple relationship between any two orderings that we define over canonical variables, in a broader sense than before. In this broad class of orderings, the General Wick Theorem (GWT) follows from the Baker-Campbell-Hausdorff identity. We point out that, generally, the characteristic function does not induce an unambiguous scheme to order the multiple products of the canonical operators
more » ... nonical operators although the value of the ordered product is unique. We construct a manifold of different schemes for each value of s of s-orderings of Cahill and Glauber.
doi:10.1088/1751-8121/aad0a6 fatcat:ib6lsydgbbcgllnlrabkk53kry