Excluding light asymmetric bosonic dark matter.

We argue that current neutron star observations exclude asymmetric bosonic noninteracting dark matter in the range from 2 keV to 16 GeV, including the 5-15 GeV range favored by DAMA and CoGeNT. If bosonic weakly interacting massive particles (WIMPs) are composite of fermions, the same limits apply provided the compositeness scale is higher than ∼10¹²  GeV (for WIMP mass ∼1  GeV). In the case of repulsive self-interactions, we exclude the large range of WIMP masses and interaction cross sections which complements the constraints imposed by observations of the Bullet Cluster.