The JWST EXCELS survey: the ages and abundances of 3 < z < 5 massive quiescent galaxies show that downsizing was already in place by z ≃ 4. - Leung, Ho-Hin; Carnall, Adam C; Taylor, Elizabeth; Stevenson, Struan D; Beverage, Aliza G; Cullen, Fergus; Dunlop, James S; McLeod, Derek J; McLure, Ross J; Begley, Ryan (Monthly Notices of the Royal Astronomical Society, 2026)