A Rutgers-led team analyzed over 14,000 ancient galaxies, creating the most detailed maps yet of dark matter’s distribution in the early universe. Despite dark matter creating vast gravitational wells where galaxies should flourish, only 3% to 7% of suitable cosmic neighborhoods actually host these glowing star factories. “We wanted to find the dark matter whose gravity drives galaxies to merge and grow. In regions where dark matter created the deepest gravitational wells, perfect for galaxy formation, most remain surprisingly empty of these bright, star-forming galaxies. By tracing their dark matter environments, scientists can essentially predict which cosmic neighborhoods will become major galactic metropolises billions of years later.