Dynamical constraints on a dark matter spike at the Galactic Centre from
  stellar orbits
  In this work I use astrometric and spectroscopic data on the S2 star at the
Galactic Centre (GC) up to 2016 to derive specific constraints on the size of a
dark matter (DM) spike around the central supermassive black hole Sgr A*. These
limits are the best direct constraints on a DM spike at the GC for
non-annihilating DM and exclude a spike with radius greater than a few tens of
parsecs for cuspy outer halos and a few hundred parsecs for cored outer halos.
