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arXiv · 2404.01838

Fourier-Matsubara series expansion for imaginary-time correlation functions

Panagiotis Tolias·Fotios Kalkavouras·Tobias Dornheim
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Abstract

A Fourier-Matsubara series expansion is derived for imaginary-time correlation functions that constitutes the imaginary-time generalization of the infinite Matsubara series for equal-time correlation functions. The expansion is consistent with all known exact properties of imaginary-time correlation functions and opens up new avenues for the utilization of quantum Monte Carlo simulation data. Moreover, the expansion drastically simplifies the computation of imaginary-time density-density correlation functions with the finite temperature version of the self-consistent dielectric formalism. Its existence underscores the utility of imaginary-time as a complementary domain for many-body physics.

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Panagiotis Tolias, Fotios Kalkavouras, Tobias Dornheim. 2024-04-02. Fourier-Matsubara series expansion for imaginary-time correlation functions. https://doi.org/10.1063/5.0211814

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