Cosmological Frontiers in Fundamental Physics 2013
We discuss holography for cosmology, focusing on a class of slow-roll inflationary spacetimes that are holographically dual to a perturbative RG flow between two nearby CFTs. The cosmological power spectrum and non-Gaussianities may be calculated directly from the dual QFT using conformal perturbation theory, even when the dual QFT is strongly coupled. Holography thus offers new methods for computing cosmological observables. To illustrate, we show how to recover the power spectrum to second order in slow roll.