What the universe's largest galaxy surveys reveal about inflation's first moments

Researchers reconstructed the primordial power spectrum—the seed pattern of density fluctuations from the Big Bang—using galaxy positions from the BOSS and eBOSS surveys. By fitting 0.3 million galaxies across billions of light-years, they recovered the spectral index n_s = 0.976, consistent with Planck satellite measurements and simple slow-roll inflation models. No exotic features or primordial gravitational waves showed up: the early universe looks disappointingly ordinary.