Résumé / Abstract Seminaire_IAP
« Inflation from the relaxation of the cosmological constant »

Alejandro Perez
Centre Physique Théorique, Luminy, Univ. Méditerranée (CPT) (Marseille, France)

We propose a model of inflation driven by the relaxation of an initially Planckian cosmological constant due to diffusion. The model can solve the horizon and flatness problem, and generate a (approximately) scale invariant spectrum of (adiabatic) primordial perturbations with the correct amplitudes and blue tilt without an inflaton. The inhomogeneities observable in the CMB arise from those associated to the fundamental Planckian granularity that are imprinted into the standard model Higgs scalar fluctuations during the inflationary phase (they are not related to quantum fluctuations in the standard way, in contrast with the usual account, a semiclassical gravity account is possible here). The process avoids, we argue, the trans-Planckian problem of standard inflationary scenarios based on the role of vacuum fluctuations. The deviations from scale invariance observed in the CMB are controlled by known parameters of the standard model of particle physics. If an order one portion of these fluctuations collapses to form primordial black holes the model produces the amount of cold dark matter required by observations.
vendredi 4 juin 2021 - 11:00
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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