Generating loop graphs via Hopf algebra in quantum field theory
arXiv:math-ph/0607036 · doi:10.1063/1.2390657
Abstract
We use the Hopf algebra structure of the time-ordered algebra of field operators to generate all connected weighted Feynman graphs in a recursive and efficient manner. The algebraic representation of the graphs is such that they can be evaluated directly as contributions to the connected n-point functions. The recursion proceeds by loop order and vertex number.
22 pages, LaTeX + AMS + eepic; new section with alternative recursion formula added, further minor changes and corrections