Dark Acoustic Oscillations and the Hubble Tension

TL;DR

This paper proposes that dark radiation-matter decoupling can produce dark acoustic oscillations, which may resolve the Hubble tension and explain recent anomalies in DESI data, providing a new avenue for cosmological models.

Contribution

It introduces a dark radiation-matter decoupling scenario predicting dark acoustic oscillations, consistent with observations and anomalies, as an alternative to existing solutions for the Hubble tension.

Findings

Evidence for dark acoustic oscillations with specific scale and amplitude

DAO properties align with DESI anomaly requirements

Scenario offers an alternative to evolving dark energy

Abstract

The Hubble tension and the recently reported anomaly in data from the Dark Energy Spectroscopic Instrument (DESI) are considered to pose serious challenges to the standard $\Lambda$CDM model of cosmology. In this work, we show that resolving the Hubble tension with a scenario featuring dark radiation-matter decoupling (DRMD) predicts the presence of dark acoustic oscillations (DAO) similar in scale to baryon acoustic oscillations (BAO). Using an inference independent of large-scale structure data, relying only on Planck measurements of the cosmic microwave background and SH$0$ES-calibrated supernova data, we find evidence for a DAO signal with drag-horizon scale $r_{d,\mathrm{DAO}} \in[54,65]\,\mathrm{Mpc}/h$ ($68\%\,\mathrm{C.I.}$) and amplitude $A_\mathrm{DAO} \in [0.02,0.05]$ ($68\%\,\mathrm{C.I.}$). These predictions provide a concrete target for current and upcoming large-scale structure surveys, including DESI, Euclid, and the Roman Space Telescope. Remarkably, the predicted DAO properties are consistent with those required to explain the DESI anomaly, offering both an alternative to evolving dark energy and a preliminary validation of the relevance of a dark radiation-matter decoupling scenario for addressing the Hubble tension.