Stellar microlensing surveys are a powerful tool for probing dark matter in the form of planetary and stellar mass compact objects (COs) in particular primordial black holes (PBHs). Under standard assumptions, current observations exclude COs in the mass range 10−11≲M/M⊙≲104 making up all of the dark matter. We provide an overview, aimed at theorists working on PBHs, of the history, theory, observational status, and future prospects of the field.
Anne M. Green (2026) studied this question.