(Non-)Conserved Currents and Cosmological Correlators
Charlotte Sleight, Massimo Taronna
TL;DR
The work investigates how global symmetries fail to persist at the late-time boundary of de Sitter space, showing that currents and the stress tensor generically acquire anomalous dimensions through shadow-based multiplet recombination. Using an EAdS reformulation of dS correlators, the authors interpret Dirichlet-boundary modes as Higgs-like states that mix with composites to gain small masses, while Neumann modes stay protected by gauge invariance. They explicitly verify the mechanism in scalar QED, Yang–Mills, and Einstein gravity, and argue for generalization to higher-spin and partially massless fields. The findings illuminate fundamental differences between AdS/CFT and dS holography, with implications for the fate of global symmetries in expanding spacetimes and for the structure of boundary correlators in cosmology.
Abstract
We study the fate of global symmetries at the late-time boundary of de Sitter space. In anti-de Sitter space, bulk gauge symmetries generally correspond to conserved global currents on the boundary. We show that in de Sitter space such currents tend to acquire anomalous dimensions due to multiplet recombination with composite operators, which is a consequence of the shadow structure of the boundary operator spectrum. As a result, global symmetries are generically (weakly) broken. This mechanism is transparent in the EAdS reformulation of dS late-time correlators given in arXiv:2007.09993 and arXiv:2109.02725, where Dirichlet modes mix with composites and acquire small masses, while Neumann modes remain protected by gauge invariance. We demonstrate this mechanism explicitly in scalar QED, Yang-Mills theory, and Einstein gravity, and argue that it extends to higher-spin and partially massless fields.
