An international research team has disproved Hawking’s theory which states that dark matter is largely composed of primordial black holes
In recent times, astronomers have been making attempts at forming a concrete understanding of the elusive dark matter. This form of matter cannot be observed as it does not interact with light or any other electromagnetic waves, however it has been confirmed as a form of matter, owing to the fact that it has mass, and can cause gravitational anomalies. Its gravitational effects, prompted renowned theoretical physicist, Stephen Hawking, to form a theory that stated dark matter was majorly formed by primordial black holes, smaller black holes ranging in mass from a fraction of a milligram, to even thousand solar masses. The theory has now been disproved by the research team, who mapped the Andromeda galaxy, to test the theory.
According to Hawking’s theory, the universe must be filled with primordial black holes, as dark matter constitutes almost 85% of the observable universe. In case a primordial black hole aligns itself with a star, the light rays emitting from the star, will be bent around the black hole, creating an illusion that the star is brighter than it seems. To test Hawking’s theory, the team took 190 consecutive images of the star system, hoping to detect an irregularity in the luminosity of the stars. However that team managed to capture almost no such instances. If Hawking’s theory had been true, the team should have been able to capture multiple such instances, suggesting that dark matter is not formed by primordial black holes.
“Previous studies had already ruled out the existence of large numbers of primordial black holes that could range in size from the mass of the Moon to about 10 solar masses. The present study rules out the presence of primordial black holes with masses comparable to the moon and sizes of about 0.1 millimetre too. This implies that at best the lunar mass primordial black holes can contribute 0.1% of all dark matter mass” says Dr. Surhud More, a member of the team.