Contributor info: Mr Kosuke Nogaki

Kosuke Nogaki, Jiani Fei, Emanuel Gull, Hiroshi Shinaoka

SciPost Phys. Codebases 19 (2023) · published 13 November 2023 | Toggle abstract · pdf

We introduce a Julia implementation of the recently proposed Nevanlinna analytic continuation method. The method is based on Nevanlinna interpolants and inherently preserves the causality of a response function due to its construction. For theoretical calculations without statistical noise, this continuation method is a powerful tool to extract real-frequency information from numerical input data on the Matsubara axis. This method has been applied to first-principles calculations of correlated materials. This paper presents its efficient and full-featured open-source implementation of the method including the Hamburger moment problem and smoothing.

Kosuke Nogaki, Jiani Fei, Emanuel Gull, Hiroshi Shinaoka

SciPost Phys. Codebases 19-r1.0 (2023) · published 13 November 2023 | Toggle abstract · src

We introduce a Julia implementation of the recently proposed Nevanlinna analytic continuation method. The method is based on Nevanlinna interpolants and inherently preserves the causality of a response function due to its construction. For theoretical calculations without statistical noise, this continuation method is a powerful tool to extract real-frequency information from numerical input data on the Matsubara axis. This method has been applied to first-principles calculations of correlated materials. This paper presents its efficient and full-featured open-source implementation of the method including the Hamburger moment problem and smoothing.