Theory HEP Seminar

osmological Inflation and the Quantum Measurement Problem

Vincent Vennin

Institut d'Astrophysique de Paris

According to cosmological inflation, the inhomogeneities in our universe are of quantum mechanical origin. This scenario is phenomenologically very appealing as it solves the puzzles of the standard hot big bang model and naturally explains why the spectrum of cosmological perturbations is almost scale invariant. It is also an ideal playground to constrain new physics and to discuss deep questions among which is the quantum measurement problem in a cosmological context. Indeed, although the large squeezing of the quantum state of the perturbations and the phenomenon of decoherence explain many aspects of the quantum to classical transition, it remains to understand how a specific outcome can be produced in the early universe, in the absence of any observer. Among the solutions currently discussed by the community is the Continuous Spontaneous Localization (CSL) approach to quantum mechanics, which has the advantage to be falsifiable. In this talk, I will apply this theory to inflation, first to challenge it with further constrains, and second to discuss some aspects of the quantum measurement problem in Cosmology.