Ramanujan Auditorium

Can we prove that cosmic structures are of quantum mechanical origin?

Vincent Vennin

LPENS, Paris

In the early universe, quantum vacuum fluctuations are amplified and stretched to large distances, giving rise to cosmological over-densities that seed the large-scale structure of our universe. However, astronomers usually analyse the data with purely classical techniques and apparently never need to rely on the quantum formalism to understand them. So are there observational signatures of the quantum origins of primordial perturbations? If confirmed, what would we learn about quantum physics in gravitational contexts?