Alleviating the Sign Problem via Contour Deformation

by Thomas C. Luu (Helmholtz-Institut für Strahlen- und Kernphysik)

Tuesday 18 Apr 2023, 12:00 → 13:00 Europe/Berlin

3.014 (PI)

I discuss my current research in using contour deformations to alleviate the numerical sign problem in stochastic simulations.  I consider deformations of various forms, ranging from simple constant offsets to those that approximate so-called Lefschetz thimbles--high-dimensional manifolds that have, in principle, no sign problem.  In the latter case I show how machine learning can be used to approximate such manifolds.  I apply these deformations to investigate low-D doped Hubbard model in various geometries.