IAS Physics Group Meeting

Abstract: I will argue on the possibility that compact extra dimensions obtain large size by higher dimensional inflation, relating the weakness of the actual gravitational force to the size of the observable universe. Although this can be realised for any number of extra dimensions, the requirement of (approximate) flat power spectrum of primordial density fluctuations consistent with present observations makes this simple proposal possible only for one or two extra dimensions at around the micron scale. I will also discuss mechanisms for stabilising the radion modulus after the end of five-dimensional inflation.