Redshift-binned constraints on the Hubble constant under <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi mathvariant="normal">Λ</mml:mi> <mml:mi>CDM</mml:mi> </mml:math> , CPL, and Padé cosmography
Motivated by recent claims of a possible redshift dependence in late-Universe determinations of the Hubble constant (H_0), we test the robustness of this behavior using multiple cosmological probes. We perform a joint redshift-binned analysis of H_0 across eight bins using late-Universe probes including Pantheon+ type Ia supernovae, Dark Energy Spectroscopic Instrument baryon acoustic oscillations, cosmic chronometers, and water megamasers under three cosmological frameworks: flat Lambda cold dark matter, Chevallier-Polarski-Linder, and Pade cosmography. Under a common baseline scheme, all three models show a qualitatively similar low-amplitude variation in the per-bin H_0 estimates. A simple Fourier-like parametrization captures this behavior, but the amplitude differs from zero only at a marginal significance of about 1.71-1.94 sigma, with similar behavior observed across all three cosmological frameworks. We then investigate the robustness and possible origin of this feature. Alternative binning schemes preserve its qualitative form, whereas single-probe per-bin fits (supernova-only, cosmic chronometer-only, BAO-only) yield ratios H_0,i / H_0,global mostly consistent with unity and do not reproduce the pronounced drift seen in the joint baseline constraints. Finally, by comparing different global versus piecewise-constant configurations for {H_0, Omega_m, M, r_d}, we find that a baselinelike oscillatory pattern reemerges only when multiple degenerate parameter combinations are allowed to vary across bins, while it is strongly suppressed when only H_0 is bin dependent. Taken together, these results indicate that the apparent oscillatory behavior of H_0(z) in late time arises from known parameter degeneracies and does not constitute robust evidence for a genuine redshift evolution.
Authors
- T. J. Zhang (ORCID: https://orcid.org/0009-0003-8997-9234)
- Anonymous
Institutions
- Beijing Normal University (CN)
- Zhengzhou University (CN)
Publication Details
- Journal
- Physical review. D/Physical review. D.
- Published
- 2026-01-21
- DOI
- https://doi.org/10.1103/cm3y-2nqq
- Primary Topic
- Cosmology and Gravitation Theories
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- China Postdoctoral Science Foundation