Observe the open universe in the sky?

We first review the related works on the observable consequence of landscape and the regulation of e-foldings during inflation. We focus on a branch of observable consequence of landscape which predicts an open universe with negative curvature if e-foldings $N>62$. After discussing the observable regulation from the aspect by Kaloper, Kleban and Sorbo, we make an argument that in the non-flat background the observable $N$ is suppressed by a factor $k/rho_{0}$. We point out that this seems to detect the information where e-foldings $N>62$ possibly. Finally, we discuss our outcomes with the recent work by Arkani-Hamed et al.

Modification from Noncommutative Inflation

We explore the noncommutative effect on single field inflation and compare with WMAP five-year data. First, we calculate the noncommutative effect from the potential and dynamical terms, and construct the general form of modified power spectrum. Second, we consider the leading order modification of slow-roll, DBI and K-inflation and unite the modification, which means the modification is nearly model independent at this level. Finally, comparing with the WMAP5 data, we find that the modified can be well realized as the origin of the relative large spectral index and the quite small running.