Could dark matter be made of black holes from a different universe?

A simulation of the ‘cosmic web’, the vast network of threads and filaments that extends throughout the Universe. Dark matter density is represented by the blue-purple colours on the left. Gas density is represented by the orange-red colours on the right. Esa

New research suggests that relic black holes from before the big bang may still shape galaxies today. These black holes could explain dark matter, one of the biggest unsolved questions in cosmology.

Generally speaking, black holes are regions of spacetime where matter is compressed into a tiny space. Dark matter, meanwhile, is matter that does not reflect or absorb light. We know it exists because of its gravitational influence on galaxies and other cosmic structures.