The Physics of Divergence

Presented by Prof. Gerald Dunne, University of Connecticut

We all know that perturbation theory is a versatile and powerful computational method of broad application in many branches of physics. Surprisingly, it turns out that perturbation theory typically diverges. I will show that this is not the disaster you might expect, but that there is in fact a very good physical reason for this strange behavior. This is a very general talk aimed particularly at students, and I will illustrate these ideas with elementary examples from quantum mechanics, atomic physics and quantum field theory. These observations provide a fascinating bridge between perturbative physics and non-perturbative physics.