Dark matter in ghost-free bigravity theory: From a galaxy scale to the   universe
  We study the origin of dark matter based on the ghost-free bigravity theory with twin matter fluids. The present cosmic acceleration can be explained by the existence of graviton mass, while dark matter is required in several cosmological situations [the galactic missing mass, the cosmic structure formation and the standard big-bang scenario (the cosmological nucleosynthesis vs the CMB observation)]. Assuming that the Compton wavelength of the massive graviton is shorter than a galactic scale, we show the bigravity theory can explain dark matter by twin matter fluid as well as the cosmic acceleration by tuning appropriate coupling constants. 
Katsuki Aoki and Kei-ichi Maeda
gr-qc astro-ph.CO hep-th