Footprints of Primordial Black Holes in the substructure of clusters
Patricio Colazo
Primordial black holes (PBHs) are objects that could have formed and evolved from the early Universe according to alternative models of inflation. These objects could constitute part or even the entirety of the dark matter budget. Their presence introduces changes that impact structure formation, feedback processes, cosmological parameters, and more. However, their existence is still being debated despite interesting pieces of indirect evidence. One of the most significant effects of PBHs is the production of more cluster substructures than expected in fiducial models, and this effect could be used to set constraints and provide observables for upcoming surveys.
In summary, the aim is to estimate the substructure excess within massive halos (such as clusters of galaxies) potentially perturbing the weak lensing effect. To achieve this, we conducted simulations to see the late-time effects that PBH imprint on the initial structure at high redshift (z~1200). We then searched for these excesses at z=0, 0.5, and 1. Our findings show that there is a clear footprint of PBH on cluster substructure compared to other dark matter candidates, such as warm dark matter. Furthermore, these changes do not alter the large-scale structure and help resolve or alleviate other potential problems within the ΛCDM model.