Transdimensional Physics and Inflation

Within the framework of a ve-dimensional brane world with a stabilized radion, we compute the cosmological perturbations generated during ination and show that the perturbations are a powerful tool to probe the physics of extra dimensions. While we nd that the power spectrum of scalar perturbations is unchanged, we show that the existence of the fth dimension is imprinted on the spectrum of gravitational waves generated during ina tion. In particular, we nd that the tensor perturbations receive a correction proportional to (HR) 2 , where H is the Hubble expansion rate during ination