New research challenges the cold dark matter assumption

Dark matter, one of the Universe’s greatest mysteries, may have been born blazing hot instead of cold and sluggish as scientists long believed. New research shows that dark matter particles could have been moving near the speed of light shortly after the Big Bang, only to cool down later and still help form galaxies. By focusing on a chaotic early era known as post-inflationary reheating, researchers reveal that “red-hot” dark matter could survive long enough to become the calm, structure-building force we see today.