1303.6244 (Yin-Zhe Ma et al.)

Confronting brane inflation with Planck and pre-Planck data    [PDF]

Yin-Zhe Ma, Qing-Guo Huang, Xin Zhang

In this paper, we compare brane inflation models with the Planck data and the pre-Planck data which combines WMAP, ACT, SPT, BAO and H0 data. The Planck data prefer a spectral index less than unity at more than 5 \sigma confidence level, and a running of the spectral index at around 2\sigma confidence level. We find that the KKLMMT model can survive at the level of 2\sigma only if \beta is less than 0.001, which indicates a certain level of fine-tuning. The IR DBI model can provide a slightly larger negative running of spectral index and red tilt, but in order to be consistent with the non-Gaussianity constraints from Planck, its parameter also needs fine-tuning in a short range.

View original: http://arxiv.org/abs/1303.6244