Astronomy & Space Science · AST-798
The Hubble Tension, Systematics & New-Physics Proposals: Physical Mechanisms
A source-linked chapter designed to teach the subject itself, not a generic lesson template.
Chapter map
Follow the actual ideas in this lesson.
The sequence below comes from this topic's published material. Sections expand or contract with the subject instead of forcing every lesson into the same five-step mold.
Mechanism
Mechanism of The Hubble Tension, Systematics & New-Physics Proposals
A calibration bias can shift local distances and therefore H0, while new early-universe physics can alter the sound horizon used to infer distances from the CMB and BAO. Proposed models include early dark energy, extra relativistic species, modified recombination, and altered gravity, but each must satisfy many other observations.
Chapter review
Assessment still in review.
The chapter is published, but its assessment has not completed the verification and QA pipeline yet. It will appear here after publication.
References & evidence
Source library for this chapter
These are the linked sources supporting the verified claims used throughout the lesson.
- 01Hubble Constant and TensionOpen source ↗
NASA Science
- 02DESI DR2 Results GuideOpen source ↗
DESI Collaboration
View claim-by-claim traceability3 verified claims
NASA's current overview describes a continuing discrepancy between late-distance-ladder and CMB-derived values.
supported · checked Sep 22, 2026The Hubble tension is the persistent mismatch between some late-universe determinations of the present expansion rate and the lower value inferred from early-universe data such as the CMB within the standard ΛCDM model.
supported · checked Sep 22, 2026A calibration bias can shift local distances and therefore H0, while new early-universe physics can alter the sound horizon used to infer distances from the CMB and BAO.
supported · checked Sep 22, 2026