Quantum effective action of multi-instanton configurations from lattice field theory

Abstract

We present a new method to compute non-perturbatively the instanton-antiinstanton interaction, using Lattice simulations. In this contribution, we test such method on the simple toy model defined by a quantum particle in a 1-dimensional double well potential. We evaluate the effective quantum interactions between instantons and antiinstantons both for a large barrier (where semiclassical arguments are supposed to hold) and for a low-barrier, where a fully non-perturbative and non-semiclassical approach is required.