Multiloop functional renormalization group for general models
Abstract
We present multiloop flow equations in the functional renormalization group (fRG) framework for the four-point vertex and self-energy, formulated for a general fermionic many-body problem. This generalizes the previously introduced vertex flow [F. B. Kugler and J. von Delft, Phys. Rev. Lett. 120, 057403 (2018)] and provides the necessary corrections to the self-energy flow in order to complete the derivative of all diagrams involved in the truncated fRG flow. Due to its iterative one-loop structure, the multiloop flow is well-suited for numerical algorithms, enabling improvement of many fRG computations. We demonstrate its equivalence to a solution of the (first-order) parquet equations in conjunction with the Schwinger-Dyson equation for the self-energy.
Keywords
Cite
@article{arxiv.1707.04536,
title = {Multiloop functional renormalization group for general models},
author = {Fabian B. Kugler and Jan von Delft},
journal= {arXiv preprint arXiv:1707.04536},
year = {2018}
}