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arXiv:2504.01163 · The Journal of Chemical Physics

Minimal pole representation for spectral functions

Lei Zhang, André Erpenbeck, Yang Yu, Emanuel Gull

Published Jun 3, 2025• 9 citations
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Abstract

Representing spectral densities, real-frequency, and real-time Green's functions of continuous systems by a small discrete set of complex poles is a ubiquitous problem in condensed matter physics, with applications ranging from quantum transport simulations to the simulation of strongly correlated electron systems. This paper introduces a method for obtaining a compact, approximate representation of these functions, based on their parameterization on the real axis and a given approximate precision. We show applications to typical spectral functions and results for structured and unstructured correlation functions of model systems.

DOI
10.1063/5.0273763

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