http://arxiv.org/abs/1608.05922
We show explicitly how the T model, E model, and Hilltop inflations are obtained from the general scalar-tensor theory of gravity with arbitrary conformal factors in the strong coupling limit. We argue that $\xi$ attractors can give any observables $n_s$ and $r$ by this method. The existence of attractors imposes a challenge to distinguish different models.
Z. Yi and Y. Gong
Wed, 23 Nov 16
14/68
Comments: 5 figures, add more discussions on f(R) model, PRD in press