Physicists Pankaj Joshi and Sudip Bhattacharyya have suggested that primordial naked singularities, formed when the universe was very young, contribute to the dark matter in the universe. They describe their research in a paper published in Journal of Cosmology and Astroparticle Physics. A preprint published in arXiv has circulated for some time and attracted attention.
Quantum fluctuations in the early universe could have produced primordial black holes (PBHs). These are black holes formed in the early universe, not from stars collapsing. Scientists believe PBHs might explain some of the dark matter in the universe. Dark matter makes up about 25% of the universe's mass but doesn't interact with light, so we can't see it directly. Like all black holes, PBHs have a singularity at their core, but an event horizon hides the singularity from view.
Joshi and Bhattacharyya's work suggests that instead of just PBHs, there might also be primordial naked singularities (PNaSs) without event horizons. These naked singularities would be potentially observable. This could offer new ways to study quantum gravity. Quantum gravity aims to explain how gravity works at the smallest scales, where quantum effects become significant.
Cosmic censorship?
If PNaSs exist and form a big part of dark matter, then observable singularities could fill much of the universe. This would not only give us a chance to see quantum gravity effects but also provide a natural lab to test theories about how gravity and quantum mechanics might work together. These singularities, as old as the universe itself, could open up new areas of physics for exploration, areas that are currently hidden in black holes.
On the other hand, many scientists believe that naked singularities do not exist. Naked singularities would break determinism and predictability in general relativity. But nature could prevent the formation of naked singularities (cosmic censorship) to keep the universe's physical laws consistent and predictable.