TY - JOUR

T1 - Microlensing by a Cluster of Primordial Black Holes

AU - Toshchenko, K. A.

AU - Baklanov, P. V.

AU - Belotsky, K. M.

AU - Blinnikov, S. I.

N1 - Toshchenko, K.A., Baklanov, P.V., Belotsky, K.M. et al. Microlensing by a Cluster of Primordial Black Holes. Astron. Lett. 51, 461–469 (2025). The modeling of the light curves for microlensing events and their statistical analysis performed by P.V. Baklanov were supported by RSF grant no. 23-12-00220. The modeling of PBH clusters performed by K.M. Belotsky was supported by RSF grant no. 23-42-00066.

PY - 2025/8

Y1 - 2025/8

N2 - Numerous programs to search for microlensing events have constrained the possibility of the existence of dark matter (DM) in the form of compact objects in the halo of our Galaxy. These constraints on the DM fraction have been obtained under the assumption of single, widely spaced objects. We investigate the microlensing by primordial black holes (PBHs) gathered into clusters. In this case, during the microlensing by PBHs the influence of both neighboring PBHs and the combined gravitational potential from the entire cluster should be taken into account, making the shape of the light curve for a microlensing event much more complicated. Events with such complex light curves are not detected in the observational MACHO, EROS, OGLE, POINT-AGAPE, and HSC experiments. It has been shown that the fraction of DM in the form of PBHs (up to for the models under study) is not recorded in these observational experiments. However, a significant fraction of PBHs that may be considered as single lenses remains for all models; therefore, PBH clustering does not allow the constraint from microlensing on the fraction of PBHs in DM to be completely lifted.

AB - Numerous programs to search for microlensing events have constrained the possibility of the existence of dark matter (DM) in the form of compact objects in the halo of our Galaxy. These constraints on the DM fraction have been obtained under the assumption of single, widely spaced objects. We investigate the microlensing by primordial black holes (PBHs) gathered into clusters. In this case, during the microlensing by PBHs the influence of both neighboring PBHs and the combined gravitational potential from the entire cluster should be taken into account, making the shape of the light curve for a microlensing event much more complicated. Events with such complex light curves are not detected in the observational MACHO, EROS, OGLE, POINT-AGAPE, and HSC experiments. It has been shown that the fraction of DM in the form of PBHs (up to for the models under study) is not recorded in these observational experiments. However, a significant fraction of PBHs that may be considered as single lenses remains for all models; therefore, PBH clustering does not allow the constraint from microlensing on the fraction of PBHs in DM to be completely lifted.

KW - black holes

KW - dark matter

KW - lensing

UR - https://www.scopus.com/pages/publications/105035465384

UR - https://www.mendeley.com/catalogue/5a6dc5a2-f5c3-3792-b8d6-92cf796d5f31/

U2 - 10.1134/S1063773725700562

DO - 10.1134/S1063773725700562

M3 - Article

VL - 51

SP - 461

EP - 469

JO - Astronomy Letters

JF - Astronomy Letters

SN - 1063-7737

IS - 8

ER -