Dilute Fermi gas at fourth order in effective field theory

C. Wellenhofer; C. Drischler; A. Schwenk

doi:10.1016/j.physletb.2020.135247

paper

Dilute Fermi gas at fourth order in effective field theory

arXiv:1812.08444 · doi:10.1016/j.physletb.2020.135247

Abstract

Using effective field theory methods, we calculate for the first time the complete fourth-order term in the Fermi-momentum or $k_{F} a_{s}$ expansion for the ground-state energy of a dilute Fermi gas. The convergence behavior of the expansion is examined for the case of spin one-half fermions and compared against quantum Monte-Carlo results, showing that the Fermi-momentum expansion is well-converged at this order for $∣ k_{F} a_{s} ∣ ≲ 0.5$ .

6 pages, 2 figures; v2: minor improvements in text, references updated, matches published version