Structure formation in a nonlocally modified gravity model

Abstract

We study a nonlocally modified gravity model proposed by Deser and Woodard [Phys. Rev. Lett. 99, 111301 (2007)] which gives an explanation for current cosmic acceleration. By deriving and solving the equations governing the evolution of the structure in the Universe, we show that this model predicts a pattern of growth that differs from standard general relativity ($+\mathrm{\text{dark energy}}$) at the 10%--30% level. These differences will be easily probed by the next generation of galaxy surveys, so the model should be tested shortly.