There’s also a theory that says that in addition to dark matter, there must also be a dark form of electromagnetism that would include other dark particles, like dark photons and dark electrons. In a recent paper, two researchers at the University of California, Davis propose a new particle that could interact with these dark particles: a dark magnetic monopole.
A monopole is a theoretical particle that acts like one end of a magnet, and the team says that a dark monopole could be a new candidate for dark matter. Even better, it would be detectable; if dark monopoles interact with dark electrons, they might mess with any regular electrons they encounter, too. We don’t yet have the technology to detect such a small interaction, but we may someday.