Redshift-binned constraints on the Hubble constant under $Λ$CDM, CPL, and Padé cosmography
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| Format: | Preprint |
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2026
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| _version_ | 1866917280661635072 |
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| author | Mo, Zhi-Yuan Jiao, Kang Zhang, Tong-Jie |
| author_facet | Mo, Zhi-Yuan Jiao, Kang Zhang, Tong-Jie |
| contents | 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. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2601_15765 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Redshift-binned constraints on the Hubble constant under $Λ$CDM, CPL, and Padé cosmography Mo, Zhi-Yuan Jiao, Kang Zhang, Tong-Jie Cosmology and Nongalactic Astrophysics 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. |
| title | Redshift-binned constraints on the Hubble constant under $Λ$CDM, CPL, and Padé cosmography |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2601.15765 |