Ward identities for the Anderson impurity model: derivation via functional methods and the exact renormalization group
Strongly Correlated Electrons
2010-08-31 v2 High Energy Physics - Theory
Abstract
Using functional methods and the exact renormalization group we derive Ward identities for the Anderson impurity model. In particular, we present a non-perturbative proof of the Yamada-Yosida identities relating certain coefficients in the low-energy expansion of the self-energy to thermodynamic particle number and spin susceptibilities of the impurity. Our proof underlines the relation of the Yamada-Yosida identities to the U(1) x U(1) symmetry associated with particle number and spin conservation in a magnetic field.
Keywords
Cite
@article{arxiv.1003.1867,
title = {Ward identities for the Anderson impurity model: derivation via functional methods and the exact renormalization group},
author = {Peter Kopietz and Lorenz Bartosch and Lucio Costa and Aldo Isidori and Alvaro Ferraz},
journal= {arXiv preprint arXiv:1003.1867},
year = {2010}
}
Comments
8 pages, corrected statements about infintite flatband limit