Multi-particle observables from a finite Euclidean spacetime

by Maxwell Hansen

Friday 20 Oct 2023, 13:00 → 14:00 Europe/London

Niels Bohr Seminar Room (Schuster)

Numerical calculations of lattice-regularized quantum field theories are a powerful tool, especially when analytic methods are not applicable. However, the utility of numerical results can be affected by two issues: (i) calculations are necessarily performed in a finite-volume spacetime and (ii) imaginary-time correlation functions are evaluated. Both aspects play an especially important role for multi-particle observables including scattering and decay amplitudes and inclusive rates. In this seminar, I will discuss progress for extracting such observables from numerical lattice field theory based on two strategies. One is to use the finite-volume as a tool, rather than an unwanted artefact, and to apply general relations between finite-volume quantities and amplitudes. The second is to carefully regulate the inverse Laplace transform, in order to estimate observables directly from numerical correlators.