Evolution of spiral galaxies in nonlocal gravity
  We study the evolution of simulated disk galaxies in the context of a
nonlocal theory of gravity. In this theory the appearance of the dark matter
problem in cosmology and astrophysics is a manifestation of the nonlocality of
the gravitational interaction. Using high-resolution N-body simulations, we
investigate the dynamical evolution of disk galaxies and compare the result
with the standard dark matter viewpoint. Specifically, we construct two
exponential galaxy models, one in nonlocal gravity (NLG) and the other
surrounded by a Plummer dark matter halo. Both systems start from the same
baryonic matter distribution, particles velocities, random velocities and the
initial Toomre's parameter. However, although the initial conditions are the
same in both models, their long-term dynamics reveals some notable differences.
For example, it turns out that the bar instability happens with higher rate in
NLG model compared with the standard case. On the other hand, at the end of the
simulation, we find that bars are weaker and faster in NLG compared with the
standard case.
