Brane Inflation After WMAP Three Year Results

Abstract

WMAP three-year data favors a red power spectrum at the level of 2 standard deviations, which provides a stringent constraint on the inflation models. In this note we use this data to constrain brane inflation models and find that KKLMMT model can not fit WMAP+SDSS data at the level of 1 standard deviation and a fine-tuning, eight parts in thousand at least, is needed at the level of 2 standard deviation.