Nonsingular bouncing cosmologies in light of BICEP2
  We confront various nonsingular bouncing cosmologies with the recently
released BICEP2 data and investigate the observational constraints on their
parameter space. In particular, within the context of the effective field
approach, we analyze the constraints on the matter bounce curvaton scenario
with a light scalar field, and the new matter bounce cosmology model in which
the universe successively experiences a period of matter contraction and an
ekpyrotic phase. Additionally, we consider three nonsingular bouncing
cosmologies obtained in the framework of modified gravity theories, namely the
Ho\v{r}ava-Lifshitz bounce model, the $f(T)$ bounce model, and loop quantum
cosmology.
