Model-Independent Perspectives on Coupled Dark Energy and the Swampland

TL;DR

This paper introduces a model-independent method to analyze coupled dark energy and the Swampland criteria, revealing mild low-redshift interactions and a potential high-redshift signal, with implications for cosmological models.

Contribution

It develops a general approach to reconstruct dark sector interactions and Swampland bounds without relying on specific models, integrating multiple cosmological data sets.

Findings

Mild evidence for dark sector interactions at low redshift.

Potential 2 sigma high-redshift interaction signal from Lyman-alpha BAO.

Implications for coupled quintessence models discussed.

Abstract

We present a general model-independent approach to study the coupled dark energy and the string Swampland criteria. We show how the dark sector interaction is degenerated with the equation of state of dark energy in the context of the expansion of the Universe. With priors for either of them, the dynamics of dark energy and the dark sector interactions can be reconstructed together with the bounds of the Swampland criteria. Combining cosmic chronometers, baryon acoustic oscillation (BAO), and Type Ia supernovae our results suggest a mild $1 \sigma$ significance of dark sector interactions at low redshift for the coupled quintessence. The Lyman-$\alpha$ BAO at $z=2.34$ leads a $2 \sigma$ signal of nonzero interactions at high redshift. The implications for coupled quintessence are discussed.