The Mass-Discrepancy Acceleration Relation: a Natural Outcome of Galaxy
  Formation in Cold Dark Matter halos
  We analyze the total and baryonic acceleration profiles of a set of
well-resolved galaxies identified in the EAGLE suite of hydrodynamic
simulations. Our runs start from the same initial conditions but adopt
different prescriptions for unresolved stellar and AGN feedback, resulting in
diverse populations of galaxies by the present day. Some of them reproduce
observed galaxy scaling relations, while others do not. However, regardless of
the feedback implementation, all of our galaxies follow closely a simple
relationship between the total and baryonic acceleration profiles, consistent
with recent observations of rotationally supported galaxies. The relation has
small scatter: different feedback implementations -- which produce different
galaxy populations -- mainly shift galaxies along the relation, rather than
perpendicular to it. Furthermore, galaxies exhibit a characteristic
acceleration, $g_{\dagger}$, above which baryons dominate the mass budget, as
observed. These observations, consistent with simple modified Newtonian
dynamics, can be accommodated within the standard cold dark matter paradigm.
