Cosmic Glitch Suggests Gravity Fades at the Universe’s Largest Scales
Researchers from the University of Waterloo and University of British Columbia propose a minimal modification to gravity—a 'cosmic glitch'—where gravity is about 1% weaker on cosmological scales (billions of light-years) than predicted by general relativity, captured by the parameter Ωg. Analyses of Planck 2018 data yield Ωg ≈ -0.0087 ± 0.0046 and a Hubble constant near 68.6 km/s/Mpc; in some data combinations this can lessen the Hubble tension, but the improvement isn't universal across all datasets. The model preserves GR on smaller scales and could be tested by future CMB and large-scale structure surveys (DESI, Euclid). If confirmed, it would hint at physics beyond general relativity at cosmic distances.