Role of three-particle vertex within dual fermion calculations
Abstract
We investigate the influence of self-energy diagrams beyond the two-particle vertex level within dual fermion theory. Specifically, we calculate the local three-particle vertex and construct from it selected dual fermion self-energy corrections to dynamical mean field theory. For the two-dimensional Hubbard model, the thus obtained self-energy corrections are small in the parameter space where dual fermion corrections based on the two-particle vertex only are small. However, in other parts of the parameter space, they are of a similar magnitude and qualitatively different from standard dual fermion theory. The high-frequency behaviour of the self-energy correction is - surprisingly - even dominated by corrections stemming from the three-particle vertex.
Keywords
Cite
@article{arxiv.1710.00648,
title = {Role of three-particle vertex within dual fermion calculations},
author = {T. Ribic and P. Gunacker and S. Iskakov and M. Wallerberger and G. Rohringer and A. N. Rubtsov and E. Gull and K. Held},
journal= {arXiv preprint arXiv:1710.00648},
year = {2017}
}