Systematic loop-level seed-correlator construction

Establish whether an equally systematic construction relating loop-level in--in correlators to conformally coupled seed correlators persists beyond the tree-level setting.

Background

The paper studies conformally coupled scalar correlators as controlled seed observables for more realistic cosmological correlators. At tree level, curvature-perturbation correlators can in suitable cases be related to conformally coupled seed correlators through weight-shifting operators and soft limits. The authors explicitly leave unresolved whether an analogous systematic relation remains available for loop-level in--in correlators.