G. Fanizza, G. Marozzi, M. Medeiros
Abstract
We apply the gradient expansion approximation to the light-cone gauge, obtaining a separate universe picture at non-linear order in perturbation theory within this framework. Thereafter, we use it to generalize the δN formalism in terms of light-cone perturbations. As a consistency check, we demonstrate the conservation of the gauge invariant curvature perturbation on uniform density hypersurface ζ at the completely non-linear level. The approach studied provides a self-consistent framework to connect at non-linear level quantities from the primordial universe, such as ζ , written in terms of the light-cone parameters, to late time observables.
Keywords
Cosmological perturbation theory; Geodesic light-cone gauge
General Relativity and Gravitation
Volume 56, Number 53
2024 May
