Resummation of Diagrammatic Series with Zero Convergence Radius for Strongly Correlated Fermions

R. Rossi, Takahiro Ohgoe, K. Van Houcke, F. Werner

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10 Citations (Scopus)


We demonstrate that a summing up series of Feynman diagrams can yield unbiased accurate results for strongly correlated fermions even when the convergence radius vanishes. We consider the unitary Fermi gas, a model of nonrelativistic fermions in three-dimensional continuous space. Diagrams are built from partially dressed or fully dressed propagators of single particles and pairs. The series is resummed by a conformal-Borel transformation that incorporates the large-order behavior and the analytic structure in the Borel plane, which are found by the instanton approach. We report highly accurate numerical results for the equation of state in the normal unpolarized regime, and reconcile experimental data with the theoretically conjectured fourth virial coefficient.

Original languageEnglish
Article number130405
JournalPhysical Review Letters
Issue number13
Publication statusPublished - 2018 Sep 27
Externally publishedYes


ASJC Scopus subject areas

  • Physics and Astronomy(all)

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