Primordial Black Holes as Dark Matter in the light of Ligo/Virgo discoveries

par Sebastien Clesse (RWTH Aachen)

jeudi 8 sept. 2016, 11:00 → 12:30 Europe/Paris

Petit Amphi (Annecy-le-Vieux)

The recent detection by Advanced LIGO of gravitational waves (GW) from the merging of a binary black hole system sets new limits on the merging rates of massive primordial black holes (PBH) that could be a significant fraction or even the totality of the dark matter in the Universe. aLIGO opens the way to the determination of the distribution and clustering of such massive PBH. If PBH clusters have a similar density to the one observed in ultra-faint dwarf galaxies, we found merging rates comparable to aLIGO expectations. Massive PBH dark matter predicts the existence of thousands of those dwarf galaxies where star formation is unlikely because of gas accretion onto PBH, which would possibly provide a solution to the missing satellite and too-big-to-fail problems. In the proposed scenario, primordial black holes are produced in the early Universe, due to the collapse of large density fluctuations generated during a phase of hybrid inflation. Such a model can be easily embedded in high-energy frameworks such as supersymmetry. Finally I will mention the possibility of using aLIGO and future GW antennas to measure the abundance and mass distribution of PBH in the range 5-200 solar masses to 10 percent accuracy, which could help to reveal their nature, with profound implications for cosmology and high energy physics.