Back to the home page of Research group in Theoretical Physics website

Theoretical Physycs Group at Scuola Normale Superiore
Piazza dei Cavalieri, 7
56100 Pisa PI - Italy
ph. +39 050 509203
ph. +39 050 509111

Marco Serone (SISSA & INFN, Trieste)

The Power of Perturbation Theory

Using a geometrical approach based on so called Lefschetz thimbles, we characterize the conditions under which the perturbative expansions in quantum mechanics lead to exact results. Even when such conditions are not met, and non-perturbative corrections are present, we explain how to define a different perturbative expansion that reproduces the full answer without advocating trans-series and non-perturbative effects, such as instantons.