Operator regularization of Feynman diagrams at multiloop order

It has been previously believed not possible to use operator regularization with Feynman diagrams, but such an option would greatly simplify matters, as operator regularization is otherwise limited to the more complicated Schwinger approach. Further, operator regularization, unlike zeta function regularization, is not limited to one-loop order, and preserves supersymmetry, unlike dimensional regularization. In this work, we investigate operator regularization at the more probing two-loop order, and find not only compatibility but that the simplification associated with Feynman diagrams is retained. (author)