Speaker
Description
In recent years, several non-stochastic algorithms have been developed for solving impurity models using the hybridization expansion, such as tensor cross interpolation, quasi–Monte Carlo integration, and sum-of-exponentials-based separation of variables.
While it is extremely hard to outperform Philipp Werner's (stochastic) continuous-time quantum Monte Carlo hybridization expansion in equilibrium, the non-stochastic direct-integration approaches have the benefit of also being applicable in real time and out of equilibrium.
I will present open-source implementations of quasi–Monte Carlo integration for the inchworm expansion and of sum-of-exponentials separation of variables applied to the bold self-energy approach, currently limited to the imaginary-time contour branch, and give an outlook on extending both approaches to the real-time non-equilibrium case.