R. Porto: The Effective Field Theory approach to the early & late Universe

by Rafael Porto (Princeton)

Thursday 7 Nov 2013, 14:00 → 15:00 Europe/Berlin

HS3 (Physikdepartment)

The last decades have seen a fantastic and steady improvement in our understanding of the early Universe, culminating with the recent release of the Planck data. Despite its marvelous accomplishments, a somewhat common sentiment in the community is that the current bounds on Non-Gaussianities from Planck have ruled out 'exotic' models for the production of primordial density fluctuations, and strongly favor 'simple' models. However, both these statements lack a robust (model-independent) support. In this talk I review a bottom up approach to Cosmology led by an Effective Field Theory (EFT) formalism, which has proven to be very successful in Particle Physics, where model independent questions may be addressed. Measurements of the CMB are limited by several effects, on the other hand Large Scale Structure (LSS) surveys appear as a natural candidate to become the next leading probe for precision Cosmology. In the last part of my talk I discuss the (Lagrangian) EFT approach to LSS (LEFT, constructed borrowing ideas from the EFT for gravitational wave emission in binary black holes) which parameterizes the information from the non-linear dynamics in a systematic fashion, thus increasing the number of modes amenable to a perturbative treatment. This is an essential step towards improving Non-Gaussiantity bounds, and ultimately addressing fundamental questions about the physics of the early universe.