Next-to-next-to-leading-order epsilon expansion for a Fermi gas at   infinite scattering length
  We extend previous work on applying the epsilon-expansion to universal properties of a cold, dilute Fermi gas in the unitary regime of infinite scattering length. We compute the ratio xi = mu/epsilon_F of chemical potential to ideal gas Fermi energy to next-to-next-to-leading order (NNLO) in epsilon=4-d, where d is the number of spatial dimensions. We also explore the nature of corrections from the order after NNLO. 
Peter Arnold, Joaquin E. Drut, and Dam Thanh Son