Bosons - Hot dark matter with small-scale power

An alternative hot dark matter scenario which considers low-mass bosons rather than neutrinos is suggested which has much more small-scale power than the neutrino hot dark matter model while keeping the power peak at large scales comparable to the comoving length scale set by neutrino free-streaming. The reason is that, for a given particle mass, the Bose-Einstein distribution has more low-velocity particles than the corresponding Fermi-Dirac distribution. Therefore, an appreciable fraction of particles stay close to their initial positions, so that even though the mean free-streaming length is similar to that for neutrinos, a fair amount of power survives on small scales. 9 refs