  The growth of a massive black hole will steepen the cold dark matter density
at the center of a galaxy into a dense spike, enhancing the prospects for
indirect detection. We study the impact of black hole spin on the density
profile using the exact Kerr geometry of the black whole in a fully
relativistic adiabatic growth framework. We find that, despite the transfer of
angular momentum from the hole to the halo, rotation increases significantly
the dark matter density close to the black hole. The gravitational effects are
still dominated by the black hole within its influence radius, but the larger
dark matter annihilation fluxes might be relevant for indirect detection
estimates.
