Fresh results (and surprises) from the James Webb Space Telescope (2/2)

by Adriano Fontana

Thursday 3 Apr 2025, 11:00 → 12:30 Europe/Zurich

500/1-001 - Main Auditorium (CERN)

The young Universe - that is, the epoch when first stars, galaxies and black holes formed in less than 0.5 Gyr after the Big Bang - is one of the most actively studied sectors of astrophysics, with deep connections to fundamental physics. In my talk (targeted to non-specialists)  I will present how recent observations - mostly obtained with the space telescope JWST and the ground-based sub-mm array ALMA -  are revolutionising our understanding of the formation of the first galaxies and their embedded Black Holes.

The physical nature of these  galaxies is challenging our models of early galaxy formation, showing that the formation of the first stars has been more efficient than previously expected.

These galaxies also appear to host Black Holes that are more numerous and massive than expected, opening the possibility that they do not descend from stellar seeds but rather from primordial black holes of different nature.

I will finally discuss how these discoveries offer a new way to provide independent constraints on some classes of non-standard cosmologies that are being proposed to address the tensions in the current Λ-CDM model.