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arXiv:1109.4794 · Physical Review A

Virial expansion with Feynman diagrams

X. Leyronas

Published Nov 29, 2011• 60 citations
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Abstract

We present a field theoretic method for the calculation of the second and third virial coefficients ${b}_{2}$ and ${b}_{3}$ of two-species fermions interacting via a contact interaction. The method is mostly analytic. We find a closed expression for ${b}_{3}$ in terms of the two- and three-body $T$ matrices. We recover numerically, at unitarity, and also in the whole Bose-Einstein-condensate--BCS crossover, previous numerical results for the third virial coefficient ${b}_{3}$.

DOI
10.1103/physreva.84.053633

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