Well some people say it could be non-baryonic, axions , sterile neutrinos , or WIMPs. It is well taking scientists a very long time to find out what dark matter is made up from.
I think some of new work seems to be pointing to axion or neutrons.
I think some of new work seems to be pointing to axion or neutrons.

Looking for Axion Dark Matter Particles Near Neutron Stars With Radio Telescopes
In the 1970s, physicists uncovered a problem with the Standard Model of particle physics—the theory that describes three of the four fundamental forces of nature (electromagnetic, weak, and strong interactions; the fourth is gravity). They found that, while the theory predicts that a symmetry betwee
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