ITP |
|
Teilchentee SS 2021
Date: 06.05.2021
Speaker: Andrei Alexandru (GW University Washington, USA)
Complex paths around the sign problem
Questions about quantum field theories at non-zero chemical potential and/or real-time correlators are often impossible to investigate numerically due to the notorious sign problem. A possible solution to this problem is to deform the integration domain for the path integral in the complex plane. We describe a number of strategies to effect such deformations, moving from the original integration domain (where the sign problem is severe) to a complex manifold where the sign fluctuations are reduced and Monte Carlo sampling works. We show how this works in a fermionic model and for computing real time correlators for a simple thermal quantum field theory.
