Exact Results in Quantum Theory & Gravity
sala 1.40, ul. Pasteura 5
2023-05-19 (14:15) 
Michael Duetsch (U. Goettingen)
Analytic regularization, addition of local counter terms and a forest formula
It is proved that the widespread method of treating UV-divergences in pert.QFT by regularization and renormalization (i.e., addition of local counter terms) can be used to construct a solution of the axioms of causal perturbation theory. First we obtain an inductive formula for the $S$-matrix, which we then solve by a "forest formula'' (corresponding to Zimmermann's forest formula for BPHZ renormalization). For scalar fields the resulting renormalization method is always applicable.