Overcomplete compact representation of two-particle Green's functions

Hiroshi Shinaoka, Junya Otsuki, Kristjan Haule, Markus Wallerberger, Emanuel Gull, Kazuyoshi Yoshimi, Masayuki Ohzeki

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


Two-particle Green's functions and the vertex functions play a critical role in theoretical frameworks for describing strongly correlated electron systems. However, numerical calculations at the two-particle level often suffer from large computation time and massive memory consumption. We derive a general expansion formula for the two-particle Green's functions in terms of an overcomplete representation based on the recently proposed "intermediate representation" basis. The expansion formula is obtained by decomposing the spectral representation of the two-particle Green's function. We demonstrate that the expansion coefficients decay exponentially, while all high-frequency and long-tail structures in the Matsubara-frequency domain are retained. This representation therefore enables efficient treatment of two-particle quantities and opens a route to the application of modern many-body theories to realistic strongly correlated electron systems.

Original languageEnglish
Article number205111
JournalPhysical Review B
Issue number20
Publication statusPublished - May 9 2018
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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