Séminaire / Seminar GReCO |
| « The non-linear Universe as a particle detector » |
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Lucas Pinol |
| Although undoubtedly successful, the inflationary paradigm is plagued by the strong degeneracy amongst its possible micro-physical mechanisms. Primordial non-Gaussianities, in the form of higher-order correlation functions, can be used to disentangle models of inflation leading to similar predictions at the linear level. Actually, I will argue that the non-linear Universe may be used as giant particle detector, unveiling the spectrum of masses and spins of the whole primordial particle content. In this talk, I will review known results and present recent progresses on how to make use of the different shapes of primordial non-Gaussianities as a diagnostic of the micro-physics of inflation. In particular, the phenomenology of multifield models of inflation will be exemplified, together with model-independent statements in the context of the effective field theory of inflationary fluctuations, and I will explain the relations between the two approaches. I will show that, generically, the soft kinematical limit of the primordial bispectrum depends not only on the mass spectrum of the theory, but also on inflationary mixing angles equivalent to the ones of neutrino and quark flavour oscillations. Finally, I will explain how “exotic” primordial non-Gaussianities, like the scalar trispectrum or tensor and mixed scalar-tensor correlations, may affect the stochastic gravitational-wave background. |
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lundi 10 octobre 2022 - 11:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |