Prof. Kostas Skenderis (University of Southampton)
I will present holographic models for the very early Universe, the period usually associated with inflation, and compare the predictions of these models against Planck 2015 data. Within the holographic framework the early Universe is described by a three dimensional QFT. Conventional inflation is included in this framework as strong coupled QFT while qualitatively new models arise when the QFT has weak or intermediate coupling. The weakly coupled models describe a very quantum early Universe and it turns out that these models fit the Planck data remarkably well, providing an alternative to LambdaCDM. Observations can be used to exclude some QFT models, while we also find models satisfying all phenomenological constraints: the data rules out the dual theory being Yang-Mills theory coupled to fermions only, but allows for Yang-Mills theory coupled to non-minimal scalars with quartic interactions.