Heavy particles are not the only interpretation for the observed coldness of 
dark matter - here I present cosmological simulations of a cold Bose-Einstein 
state, revealing an unknown world of non-linear wave structures that 
distinguish this physically well motivated state from standard particle CDM. 
The key predictions are made with GPU optimised AMR evolution of coupled 
Schrodinger-Poisson equations, finding solitonic cores and a granular 
structure within virialised halos. Comparison with the latest Hubble Frontier 
Field galaxies that we have detected at high redshift favours this 
interpretation, as do the large cores derived for dwarf galaxies and by QSO 
flux anomalies. This exploration is timely because of the continued 
laboratory absence of WIMPs, and may establish light bosons as the most 
viable interpretation of dark matter.