Perturbation spectra and renormalization-group techniques in double-field inflation and quantum gravity cosmology

Abstract We study primordial cosmology with two scalar fields that participate in inflation at the same time, by coupling quantum gravity (i.e., theory R+R 2 +C fakeon prescription/projection for C ) to a field quadratic potential. show there exists perturbative regime can be described an asymptotically de Sitter, cosmic RG flow couplings. Since degrees of freedom mix nontrivial ways, adiabatic and isocurvature perturbations are not invariant on superhorizon scales. It is possible identify correct using invariance as guiding principle. work out resulting power spectra tensor NNLL NLL orders, respectively. An unexpected consequence remains predictive. Indeed, mixing affects only subleading corrections, so predictions single-field confirmed leading order.