  A trapped Bose-Einstein condensate, being strongly perturbed, exhibits
several spatial structures. First, there appear quantum vortices. Increasing
the amount of the injected energy leads to the formation of vortex tangles
representing quantum vortex turbulence. Continuing energy injection makes the
system so strongly perturbed that vortices become destroyed and there develops
another kind of spatial structures with essentially heterogeneous spatial
density. These structures consist of high-density droplets, or grains,
surrounded by the regions of low density. The droplets are randomly distributed
in space, where they can move; however they live sufficiently long time to be
treated as a type of metastable creatures. Such structures have been observed
in nonequilibrium trapped Bose gases of $^{87}$Rb subject to the action of an
oscillatory perturbation modulating the trapping potential. Perturbing the
system even stronger transforms the droplet structure into wave turbulence,
where Bose condensate is destroyed. Numerical simulations are in good agreement
with experimental observations.
