Arkani-Hamed, NimaCheng, Hsin-ChiaCreminelli, PaoloRandall, Lisa2019-09-272003Arkani-Hamed, Nima, Hsin-Chia Cheng, Paolo Creminelli, and Lisa Randall. 2003. “Extranatural Inflation.” Physical Review Letters 90 (22). https://doi.org/10.1103/physrevlett.90.221302.0031-90071079-71141092-0145http://nrs.harvard.edu/urn-3:HUL.InstRepos:41417286We present a new model of inflation in which the inflaton is the extra component of a gauge field in a 5D theory compactified on a circle. The chief merit of this model is that the potential comes only from nonlocal effects so that its flatness is not spoiled by higher-dimensional operators or quantum gravity corrections. The model predicts a red spectrum (nsimilar or equal to0.96) and a significant production of gravitational waves (rsimilar or equal to0.11). We also comment on the relevance of this idea to quintessence.en-USJournal Article2019-09-2710.1103/PhysRevLett.90.221302