Sommaire:

I review recent progress in understanding the dynamics of light self-interacting scalar fields in de Sitter space at low (superhorizon) momenta. In this regime, perturbation theory is plagued by secular/infrared divergences due to the gravitational amplification of long wavelength quantum fluctuation and a correct description requires resummation schemes and/or nonperturbative tools. I present recent advances based on solutions of the Dyson-Schwinger equations and on nonperturbative renormalization group techniques. The gravitationally enhanced infrared fluctuations trigger dramatic phenomena such as the radiative restoration of spontaneously broken continuous symmetries.

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Pour plus d'informations, merci de contacter Kneur J.-L.