The removal of cusps from galaxy centres by stellar feedback in the early Universe

A cosmological paradoxAlthough the standard cosmological model describes the large-scale structure of the Universe successfully, it does less well on a smaller scale. For instance the model predicts a lower dark-matter density at the centre of nearby galaxies (a cusp or dip in density profile) than is seen in observations, which suggest that galactic dark matter haloes have a 'flat' central core. Mashchenko et al. resolve this paradox with …