13 Mar/24
11:30 - 12:30 (Europe/Zurich)

A primordial black hole tale


4/2-011 at CERN

Primordial black holes (PBHs) are black holes generated by the collapse of overdense regions in the early Universe. The presence of a population of black holes deeply impacts the history of the Universe from large scales (Gpc) to small scales (<pc). First, I will discuss the effects of PBHs accretion on the cosmic backgrounds emission (from X-ray to Near Infrared, and radio), and how the produced radiation feedback affects the thermal history of the Universe. We developed a semi-analytic model to evaluate the amount of light produced by PBHs accretion during the cosmic history, and if PBHs could be the sources of the observed backgrounds excesses. Then, I will describe PBHs in the context of supermassive black holes (SMBHs) formation, which is still an open problem. The newest James Webb Space Telescope (JWST) observations are indeed pushing the horizon of the observed SMBHs to higher redshift, challenging the most popular assembly scenarios. PBHs could represent a new solution to explain the presence of SMBHs in the first Gyr of the Universe. Stellar mass PBHs can gather and merge in the central part of high redshift dark matter halos forming SMBHs seeds.  I will present how the results of the proposed model are in agreement with the latest JWST observations.