  Experimental advances in synthesizing spin-orbit couplings in cold atomic
Bose gases promise to create single-particle dispersion laws featuring energy
minima that are degenerate on a ring or a sphere in momentum space. We show
that for arbitrary space dimensionality the ground-state properties of a dilute
system of spin-orbit coupled Bose particles with such dispersion and
short-range repulsive interactions are universal: the chemical potential
exhibits a quadratic dependence on the particle density as found in a
one-dimensional free Fermi gas.
