How dark matter could hide from every detector we build

Standard dark matter models require particles to stay in contact with the Standard Model until freeze-out. These researchers show that dark matter can achieve the correct relic density even if it separates from ordinary matter at temperatures far above its own mass, then cools independently. The trick: the two sectors end up at similar temperatures during freeze-out by coincidence, giving the right abundance without direct contact. This opens a hiding place for dark matter where neither underground detectors nor particle colliders can find it.