3 papers
cond-mat.str-el2025
Compressing local vertex functions from the multipoint numerical renormalization group using quantics tensor cross interpolation
Markus Frankenbach, Marc Ritter, Mathias Pelz +3
The multipoint numerical renormalization group (mpNRG) is a powerful impurity solver that provides accurate spectral data useful for computing local, dynamic correlation functions…
cond-mat.str-el2025
Testing the parquet equations and the U(1) Ward identity for real-frequency correlation functions from the multipoint numerical renormalization group
Nepomuk Ritz, Anxiang Ge, Markus Frankenbach +3
Recently, it has become possible to compute real-frequency four-point correlation functions of quantum impurity models using a multipoint extension of the numerical renormalization…
cond-mat.str-el2024
KeldyshQFT: A C++ codebase for real-frequency multiloop functional renormalization group and parquet computations of the single-impurity Anderson model
Nepomuk Ritz, Anxiang Ge, Elias Walter +3
We provide a detailed exposition of our computational framework designed for the accurate calculation of real-frequency dynamical correlation functions of the single-impurity Ander…