Implications of DESI for Dark Matter & Cosmic Birefringence

TL;DR

This paper investigates a unified dark matter-dark energy model that explains early-time dark energy behavior, cosmic birefringence, and DM relic abundance, aligning with recent DESI data and CMB polarization observations.

Contribution

It introduces a novel interacting DM-DE framework that naturally accounts for dynamical DE crossing the phantom barrier and explains DM relic abundance without extra fields.

Findings

Effective dynamical DE crossing the phantom barrier at early times.

Alignment with DESI data on dark energy behavior.

Explanation of cosmic birefringence and DM relic abundance.

Abstract

We explore an interacting dark matter (DM)-dark energy (DE) framework that naturally yields an effective dynamical DE equation of state crossing the phantom barrier at early times, as indicated by recent DESI data, while also accounting for the observed isotropic rotation of the cosmic microwave background (CMB) linear polarization. Within this unified framework, we also explain the DM relic abundance without introducing additional fields or couplings. Depending on the DE potential, we identify two viable scenarios: a superheavy freeze-in DM requiring a high reheating temperature, or a strongly interacting dark sector with a GeV-TeV scale thermal DM candidate.