Overcomplete compact representation of two-particle Green's functions
Abstract
Two-particle Green's functions and the vertex functions play a critical role in theoretical frameworks for describing strongly correlated electron systems. However, numerical calculations at two-particle level often suffer from large computation time and massive memory consumption. We derive a general expansion formula for the two-particle Green's functions in terms of an overcomplete representation based on the recently proposed "intermediate representation" basis. The expansion formula is obtained by decomposing the spectral representation of the two-particle Green's function. We demonstrate that the expansion coefficients decay exponentially, while all high-frequency and long-tail structures in the Matsubara-frequency domain are retained. This representation therefore enables efficient treatment of two-particle quantities and opens a route to the application of modern many-body theories to realistic strongly correlated electron systems.
Cite
@article{arxiv.1803.01916,
title = {Overcomplete compact representation of two-particle Green's functions},
author = {Hiroshi Shinaoka and Junya Otsuki and Kristjan Haule and Markus Wallerberger and Emanuel Gull and Kazuyoshi Yoshimi and Masayuki Ohzeki},
journal= {arXiv preprint arXiv:1803.01916},
year = {2018}
}
Comments
17 pages, 12 figures (minor modifications)