Brane inflation revisited after WMAP five-year results

Understand

In this paper, we revisit brane inflation models with the WMAP five-year results.

• The WMAP five-year data favor a red-tilted power spectrum of primordial fluctuations at the level of two standard deviations, which is the same as the WMAP three-year result qualitatively, but quantitatively the spectral index is slightly greater than the three-year value.
• This result can bring impacts on brane inflation models.
• According to the WMAP five-year data, we find that the KKLMMT model can survive at the level of one standard deviation, and the fine-tuning of the parameter $\beta$ can be alleviated to a certain extent at the level of two standard deviations.