Overview
- Secrest et al. report in Reviews of Modern Physics (2025) that the Universe fails the Ellis–Baldwin test comparing matter and CMB dipoles.
- The measured dipole directions align but the amplitudes disagree, contradicting expectations under the FLRW/Lambda‑CDM framework.
- Independent radio and mid‑infrared catalogs show the same amplitude mismatch, reducing the likelihood of a single-instrument systematic.
- Authors describe the anomaly as a serious challenge to the standard cosmological model and its assumption of large‑scale isotropy.
- Forthcoming datasets from Euclid, SPHEREx, the Vera Rubin Observatory, and the Square Kilometre Array are expected to adjudicate the result.