Variety of cosmic acceleration models from massive $F(R)$ bigravity
  We study the accelerating cosmology in massive $F(R)$ bigravity via the reconstruction scheme. The consistent solution of the FRW equations is presented: it includes Big and Little Rip, quintessence, de Sitter and decelerating universes described by the physical $g$ metric while the corresponding solution of the universe described by the reference $f$ metric is also found. It is demonstrated that in general the cosmological singularities of $g$ metric are not always manifested as cosmological singularities of the reference $f$ metric. We give two consistent ways to describe the Big and Little Rip, quintessence, de Sitter and decelerating universes. In one of the consistent solutions, the two metrics $g$ and $f$ coincide with each other, which may indicate the connection with the convenient single metric background formulation. For another solution, where two metrics $g$ and $f$ do not coincide with each other, here always appears super-luminal mode. 
Shin'ichi Nojiri, Sergei D. Odintsov, and Norihito Shirai
hep-th astro-ph.CO gr-qc