Abstract
Four-dimensional supergravity theories admit limits along which gravity decouples. In these limits, some fields acquire rigid couplings while others remain gravitational, and BPS objects like particles, strings, and membranes split into extremal and non-extremal, in line with Swampland expectations. In this talk, I analyse this decoupling mechanism for limits exhibiting axionic shift symmetries, in the context of 4d N=2 and N=1 Calabi–Yau compactifications. The axions select a preferred choice of Kähler potential, which simultaneously determines a maximal cutoff for a rigid theory. Using this Kähler frame and the spectrum of BPS objects, one can systematically identify the gravitational and rigid EFT sectors, as well as the rigid subsector that fully decouples from gravity. Generically, such decoupling is accompanied by a divergence in the field-space scalar curvature.