%0 Journal Article
%T Conformal Symmetries of Adiabatic Modes in Cosmology
%A Kurt Hinterbichler
%A Lam Hui
%A Justin Khoury
%J Physics
%D 2012
%I arXiv
%R 10.1088/1475-7516/2012/08/017
%X We remark on the existence of non-linearly realized conformal symmetries for scalar adiabatic perturbations in cosmology. These conformal symmetries are present for any cosmological background, beyond any slow-roll or quasi-de Sitter approximation. The dilatation transformation shifts the curvature perturbation by a constant, and corresponds to the well-known symmetry under spatial rescaling. We argue that the scalar sector is also invariant under special conformal transformations, which shift the curvature perturbation by a term linear in the spatial coordinates. We discuss whether these conformal symmetries can be extended to include tensor perturbations. Tensor modes introduce their own set of non-linearly realized symmetries. We identify an infinite set of large gauge transformations which maintain the transverse, traceless gauge condition, while shifting the tensor mode non-trivially.
%U http://arxiv.org/abs/1203.6351v1