Evidence of the pair-instability gap from black-hole masses - Hui Tong; Maya Fishbach; Eric Thrane; Matthew Mould; Thomas A. Callister; Amanda M. Farah; Nir Guttman; Sharan Banagiri; Daniel Beltran-Martinez; Ben Farr; Shanika Galaudage; Jaxen Godfrey; et al. (Nature, 2026)