An ode to instantons

22.04.2026 11:00 – 12:00

I will present a novel formalism for semiclassical time evolution in quantum mechanics. By identifying complex saddle points of the path integral in real time, real saddles in complex time, and complex saddles in complex time, we reproduce the known answers to classic problems to one loop.
For the decay of a metastable state, there are finite-time and finite-energy analogs of the Euclidean "bounce" which, notably, do not possess strict zero or negative modes.

The motivation of this work is to learn how to compute decay rates in quantum field theory in situations with non-trivial time dependence, by first taking a humble step back into the fascinating world of quantum mechanics.

Based on arXiv:2603.06575, in collaboration with Oliver Janssen, Joel Karlsson and Flavio Riccardi

Lieu

Bâtiment: Ecole de Physique

EP234

entrée libre