1212.2079 (Shin'ichi Nojiri et al.)

Variety of cosmic acceleration models from massive $F(R)$ bigravity    [PDF]

Shin'ichi Nojiri, Sergei D. Odintsov, Norihito Shirai

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 manifested as cosmological singularities of the reference $f$ metric. However, there are models where cosmological singularity does not occur in the universe described by $g$ metric while it occurs in $f$ universe and vice-versa. Alternatively, the structure of singularity may change (Big Rip in $f$ universe becomes Little Rip in $g$ universe). The consistent solution describing Big and Little Rip, quintessence, de Sitter and decelerating universes for coinciding $g$ and $f$ metrics is established, indicating the connection with the convenient single metric background formulation. The possible relation between super-luminal particle observation as manifestation of reference metric (or better to say, of massive graviton) is briefly discussed.

View original: http://arxiv.org/abs/1212.2079