Hiroshi Shinaoka, Dominique Geffroy, Markus Wallerberger, Junya Otsuki, Kazuyoshi Yoshimi, Emanuel Gull, Jan Kuneš
SciPost Phys. 8, 012 (2020) ·
published 28 January 2020

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Manybody calculations at the twoparticle level require a compact
representation of twoparticle Green's functions. In this paper, we introduce a
sparse sampling scheme in the Matsubara frequency domain as well as a tensor
network representation for twoparticle Green's functions. The sparse sampling
is based on the intermediate representation basis and allows an accurate
extraction of the generalized susceptibility from a reduced set of Matsubara
frequencies. The tensor network representation provides a system independent
way to compress the information carried by twoparticle Green's functions. We
demonstrate efficiency of the present scheme for calculations of static and
dynamic susceptibilities in single and twoband Hubbard models in the
framework of dynamical meanfield theory.