2024/05/23 by E. Mediavilla, Mediavilla, E., J. Jiménez-Vicente +1
Physics and Astronomy · #Astrophysics and Star Formation Studies #Atomic and Molecular Physics #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences
paper · pdf · doi:10.48550/arxiv.2405.14984
openalex publication_date 2024/05/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Gravitational microlensing is a robust tool to detect and directly measure the abundance and mass of any kind of compact objects, either in our galaxy or in the extragalatic domain. On basis to generic, broadly applicable arguments, it is concluded that the observed microlensing magnifications are too small and the microlensing events less frequent than the expectations for a significant population of compact objects (other than normal stars). The detection of chromatic effects of microlensing, neither supports the presence of BHs. Detailed statistical studies of the observed microlensing magnifications and events frequency impose strict upper limits to the fraction of total mass of BHs (\ltsim 1%) from 10-7M_\odot to indefinitely large masses. These results hold even when the BHs are distributed according to a mass spectrum or are forming clusters.