Dark Walker in the Early Universe: A Strongly Coupled Sector Model

TL;DR

This paper investigates a strongly coupled dark sector model called Dark Walker, which during inflation produces non-Gaussianities and can explain dark matter relic abundance via freeze-in, linking early universe dynamics to current dark matter observations.

Contribution

It introduces a novel strongly coupled dark sector model that connects inflationary non-Gaussianities with dark matter production through Higgs portal interactions.

Findings

Dark Walker generates primordial non-Gaussianities during inflation.

The model accounts for dark matter relic abundance via freeze-in.

It provides a predictive link between inflationary dynamics and dark matter.

Abstract

We explore the phenomenology of the ``Dark Walker'' -- an $\text{SU}(3)$ theory with eight flavors of massless fundamental fermions in the dark sector. During inflation, its walking dynamics generate primordial non-Gaussianities through the exchange of unparticles, while accounting for the current dark matter relic abundance if we consider freeze-in of Dark Walker coupled to the Standard Model through the Higgs portal. This provides a simple yet predictive example linking strongly coupled inflationary dynamics to present-day dark matter.