articlePhysical Review LettersJan 12, 2026GREEN OA

Addressing Tensions in Λ CDM Cosmology by an Increase in the Optical Depth to Reionization

Lawrence Berkeley National Laboratory · University of California, Berkeley

PubMed
Indexed inarxivcrossrefdatacitepubmed

Abstract

Recent baryonic acoustic oscillation (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI) are mildly discrepant (2.2σ) with the cosmic microwave background (CMB) when interpreted within ΛCDM. When analyzing these data with extended cosmologies this inconsistency manifests as a ≃3σ preference for subminimal neutrino mass or evolving dark energy. It is known that the preference for subminimal neutrino mass from the suppression of structure growth could be alleviated by increasing the optical depth to reionization τ. We show that, because the CMB-inferred τ is negatively correlated with the matter fraction, a larger optical depth resolves a similar preference from geometric constraints. Optical…

Citation impact

5
total citations
FWCI
33.95
Percentile
99%
References
78
Citations per year

Authors

4

Topics & keywords

Keywords
  • Cosmic microwave background
  • Planck
  • Reionization
  • Dark energy
  • Cosmic variance
  • Neutrino
  • Cosmology
  • Dark matter
No related works found for this paper.

Funding