Can mysterious early galaxies measure the universe's expansion rate?

Researchers propose using quasi-periodic variations in 'little red dots'—early supermassive black holes wrapped in dense gas—as standard candles to measure cosmic expansion. They derive a period-luminosity relation analogous to stellar pulsations and test it on one lensed object, yielding a preliminary Hubble constant measurement with 40% uncertainty. With a decade of monitoring, the method could shrink errors to 3–20%, offering a novel early-universe distance probe independent of traditional ladders.