2021/10/31 by Luca Ferialdi, L. Ferialdi, L. Diósi +1
Mathematics · Physics and Astronomy · #Connection (principal bundle) #Discrete mathematics #Mathematics #Operator (biology) #Pure mathematics #Quantum Mechanics and Non-Hermitian Physics #Random Matrices and Applications #Spectral Theory in Mathematical Physics #hep-th #math-ph #math.MP #quant-ph
paper · pdf · doi:10.1103/physreva.104.052209
published in Physical Review A 104(5) (American Physical Society)
arxiv created 2021/11/15 · openalex publication_date 2021/11/15 · arxiv updated 2021/11/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Wick's theorem provides a connection between time ordered products of bosonic or fermionic fields, and their normal ordered counterparts. We consider a generic pair of operator orderings and we prove, by induction, the theorem that relates them. We name this the general Wick's theorem (GWT) because it carries Wick's theorem as special instance, when one applies the GWT to time and normal orderings. We establish the GWT both for bosonic and fermionic operators, i.e., operators that satisfy c-number commutation and anticommutation relations respectively. We remarkably show that the GWT is the same, independent of the type of operator involved. By means of a few examples, we show how the GWT helps treat demanding problems by reducing the amount of calculations required.