Is Dark Matter Made of Black Holes?
Gravitational wave detectors, LIGO and Virgo, have detected a population of massive black holes whose origin is one of the biggest mysteries in modern astronomy. According to one hypothesis, these objects may have formed in the very early Universe and may compose dark matter, a mysterious substance filling the Universe. A team of scientists from the OGLE (Optical Gravitational Lensing Experiment) survey from the Astronomical Observatory of the University of Warsaw have announced the results of nearly 20-year-long observations indicating that such massive black holes may comprise at most a few percent of dark matter. Another explanation, therefore, is needed for gravitational wave sources. The results of the study were published in two articles, in Nature and the Astrophysical Journal Supplement Series.