From low-density neutron matter to the unitary limit

Various quantities of an attractively interacting fermion system at the unitary limit are determined by extrapolating Monte Carlo results of low-density neutron matter. Smooth extrapolation in terms of 1/(k(F)a(0)) (k(F) is the Fermi momentum, and a(0) is the S-1(0) scattering length) is found with the quantities examined: the ground-state energy, the pairing gap at T approximate to 0, and the critical temperature of the normal-to-superfluid phase transition. We emphasize proximity of the physics of low-density neutron matter to that at the unitary limit. The extrapolated quantities are in a reasonable agreement with those in the literature.