Cosmology with Equivalence Principle Breaking in the Dark Sector
  A long-range force acting only between nonbaryonic particles would be
associated with a large violation of the weak equivalence principle. We explore
cosmological consequences of this idea, which we label ReBEL (daRk Breaking
Equivalence principLe). A high resolution hydrodynamical simulation of the
distributions of baryons and dark matter confirms our previous findings that a
ReBEL force of comparable strength to gravity on comoving scales of about 1
Mpc/h causes voids between the concentrations of large galaxies to be more
nearly empty, suppresses accretion of intergalactic matter onto galaxies at low
redshift, and produces an early generation of dense dark matter halos. A
preliminary analysis indicates the ReBEL scenario is consistent with the
one-dimensional power spectrum of the Lyman-Alpha forest and the
three-dimensional galaxy auto-correlation function. Segregation of baryons and
DM in galaxies and systems of galaxies is a strong prediction of ReBEL. ReBEL
naturally correlates the baryon mass fraction in groups and clusters of
galaxies with the system mass, in agreement with recent measurements.
