  We study the distribution of vortex lines in a three-dimensional lattice with
inhomogeneous couplings. We investigate the spatial distribution of the number
of vortex lines, showing how the vortex lines are expelled from the region with
higher couplings. Results for the correlation functions are presented, together
with a discussion of the implications of the obtained results for the vortex
distribution in ultracold trapped gases and in neutron stars.
