Dark Acoustic Oscillations as an Early-Universe Explanation of the DESI Anomaly

Abstract

DESI DR2 data have been widely interpreted as evidence for late-time evolving dark energy (DE) with an apparent phantom crossing. Here we investigate an alternative explanation, based on early-Universe physics. If dark acoustic oscillations (DAO) are close in scale to baryon acoustic oscillations (BAO), they can bias the extraction of the BAO scale from the peak in the galaxy correlation function. This leads to an apparent shift in the inferred distance if the superposition of BAO and DAO features is misinterpreted as being due to BAO only. Taking this shift into account, we find that a DAO with percent-level amplitude can reconcile DESI DR2 with Planck 2018 as well as Pantheon+ supernovae data, with fit improvement at a similar level compared to evolving DE. Notably, a DAO feature with the required properties has been predicted in a previously proposed scenario that resolves the Hubble tension via a pre-recombination decoupling of dark matter and dark radiation (DRMD). The presence of a DAO feature close to the BAO peak can be scrutinized with future full-shape galaxy clustering data from DESI and Euclid.

17 pages, 5 figures, 2 tables; likelihood code available at https://github.com/NEDE-Cosmo/DAO_bias_DESI_DR2; published in PRD

References in corpus (28)

• A Comprehensive Measurement of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncertainty from the Hubble Space Telescope and the SH0ES Team
• The Pantheon+ Analysis: Cosmological Constraints
• The trouble with $H_0$
• Cobaya: Code for Bayesian Analysis of hierarchical physical models
• DESI DR2 Results II: Measurements of Baryon Acoustic Oscillations and Cosmological Constraints
• Resumming Cosmological Perturbations via the Lagrangian Picture: One-loop Results in Real Space and in Redshift Space
• On the Robustness of the Acoustic Scale in the Low-Redshift Clustering of Matter
• Resolving the Hubble Tension with New Early Dark Energy
• Interacting radiation after Planck and its implications for the Hubble Tension
• Symmetry of Cosmological Observables, and a High Hubble Constant as an Indicator of a Mirror World Dark Sector
• Hot New Early Dark Energy
• Sterile neutrino self-interactions: $H_0$ tension and short-baseline anomalies
• Baryon Acoustic Oscillation Theory and Modelling Systematics for the DESI 2024 results
• Generalized Galilean Genesis
• Hot New Early Dark Energy: Towards a Unified Dark Sector of Neutrinos, Dark Energy and Dark Matter
• Beware of commonly used approximations II: estimating systematic biases in the best-fit parameters
• The Local Distance Network: a community consensus report on the measurement of the Hubble constant at 1% precision
• Cold New Early Dark Energy pulls the trigger on the $H_0$ and $S_8$ tensions: a simultaneous solution to both tensions without new ingredients
• Two-Loop Master Integrals for Leading-Color $pp\to t\bar{t}H$ Amplitudes with a Light-Quark Loop
• Simulating cosmologies beyond $\Lambda$CDM with PINOCCHIO
• Dispu$\tau$able: the high cost of a low optical depth
• Examining Quintessence Models with DESI Data
• Towards a Realistic Model of Dark Atoms to Resolve the Hubble Tension
• Resolving the Planck-DESI tension by nonminimally coupled quintessence
• Gravitational wave oscillations in bimetric cosmology
• Searching for light neutralinos with a displaced vertex at the LHC
• Revisiting electroweak radiative corrections to $b\to s\ell \ell$ in SMEFT
• Unified dark fluid with null sound speed as an alternative to phantom dark energy