Black hole collisions leave a permanent "scar" on the fabric of space that could prove Einstein was slightly wrong.
April 14, 2026
Original Paper
Gravitational Memory from Hairy Binary Black Hole Mergers
arXiv · 2604.09350
The Takeaway
A 4% difference in "gravitational memory" exists between standard relativity and new theories that include "hairy" black holes. Detecting this tiny, permanent displacement of spacetime would provide the first definitive proof of physics beyond General Relativity.
From the abstract
Gravitational-wave memory is a low-frequency, non-oscillatory component of the radiation field that provides a potentially powerful but as yet undetected probe of strong-field gravity. We present the first calculation of gravitational memory from full inspiral--merger--ringdown waveforms in a theory beyond general relativity, focusing on scalar-Gauss-Bonnet gravity as a theoretically well-motivated and numerically accessible extension of GR. Starting from the general memory formulas in Horndeski