Can gravitational waves map when stars formed most furiously?

Black hole mergers trace back to when their progenitor stars were born, making them a gravitational-wave census of cosmic star formation — completely independent of light-based surveys that struggle with dust and calibration uncertainties. Simulating one year of observations with the planned LIGO A# upgrade, the authors show the merger-rate peak (around redshift 1.5, roughly 9 billion years ago) can be pinned down to ±0.1. Next-generation detectors like Cosmic Explorer and Einstein Telescope would tighten that to ±0.02.