Rencontres franciliennes de cosmologie primordiale

jeudi 21 mars 2019, 09:00 → 17:00 Europe/Paris

Salle des seminaires (Institut d'Astrophysique de Paris)

Julien Grain (Institut d'Astrophysique Spatiale), Sébastien Renaux-Petel (IAP-CNRS), Serreau Serreau (APC, Universite Paris Diderot), Vincent Vennin (APC Paris), Filippo Vernizzi (IPhT - CEA Saclay), Yashar Akrami (Département de Physique, École Normale Supérieure (ENS))

We acknowledge financial support from the PNCG, the labex P2IO and the FRIF.

 

09:00 → 09:30 Doors opening

09:30 → 09:40 Opening and welcome forewords

09:40 → 11:00 The cosmological bootstrap

Orateur: Prof. Daniel Baumann (Amsterdam University)

11:00 → 11:30 Coffee break

11:30 → 12:00 Inflation with strongly non-geodesic motion: motivation, theoretical consistency and observational signatures

Orateur: Lucas Pinol (IAP)

12:00 → 12:45 Discussion

12:45 → 14:00 Lunch break

14:00 → 14:30 Backreaction of the infrared modes of scalar fields on de Sitter geometry

We study the back-reaction of the infrared modes of an O(N) theory in a classical de Sitter background. We use the nonperturbative renormalization group methods to extract the flow of the Hubble constant as we integrate the gravitationally enhanced long wavelength modes. The scalar theory flows towards an effective zero dimensional theory for the super-horizon modes, which allows to perform analytical computations. For a massless theory, the interactions tend to renormalize negatively the Hubble constant, thus drawing energy from the classical gravitational field. This phenomenon saturates however, due to the generation of a mass. Also, in the case of a broken symmetry, we show that the goldstone modes don't contribute to the flow.

Orateur: Gabriel Moreau (Université Paris Diderot)

14:30 → 15:00 Discussion

15:00 → 15:30 Coffee break

15:30 → 16:00 (De)stabilization of the Higgs vacuum during inflation

Orateur: Dr Jacopo Fumagalli (IAP)

16:00 → 17:00 Discussion