Speaker
Description
Microlensing experiments searching for MACHOs (massive astrophysical compact halo object, MACHO) have limited the possibility of the existence of dark matter in the form of MACHOs. These constraints on the fraction of dark matter are made for single MACHOs. The microlensing light curve for single MACHOs agrees well with the standard microlensing model. However, the mutual influence of clustered MACHOs can significantly change the light curves and therefore change the constraints on the MACHO fraction.
We have simulated microlensing events for models of the class of clustered primordial black holes (PBH). The analysis of microlensing events for these cluster models showed that the fraction of MACHO mass that is not detected as single ones can reach up to 40%. Therefore, observations of experiments such as MCHO, EROS, OGLE, POINT-AGAPE, HSC can impose tighter constraints on the fraction of MACHOs. Although the models of PBH clusters that we consider reduce the limitations due to clustering, it is not possible to completely remove the limitations on MACHO.
