  We show that there exists a systematic expansion around four spatial
dimensions for Fermi gas in the unitarity regime. We perform the calculations
to leading and next-to-leading orders in the expansion over epsilon=4-d, where
d is the dimensionality of space. We find the ratio of chemical potential and
Fermi energy to be mu/eF=1/2 epsilon^3/2 + 1/16 epsilon^5/2 ln epsilon -0.0246
epsilon^5/2 and the ratio of the gap in the fermion quasiparticle spectrum and
the chemical potential to be Delta/mu=2/epsilon-0.691. The minimum of the
fermion dispersion curve is located at |p|=(2m epsilon_0)^1/2 where
epsilon_0/mu=2+O(epsilon). Extrapolation to d=3 gives results consistent with
Monte Carlo simulations.
