Mapping the redshift drift at various redshifts through cosmography

Fuente: arXiv
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Main Authors: Alfano, Anna Chiara, Luongo, Orlando
Format: Preprint
Published: 2026
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author Alfano, Anna Chiara
Luongo, Orlando
author_facet Alfano, Anna Chiara
Luongo, Orlando
contents The redshift drift provides a kinematic test of the cosmic expansion history through the slow time variation of the redshift of comoving sources. Motivated by the expected Sandage-Loeb measurements from future facilities, we investigate the drift within a cosmographic framework, modeling the Hubble rate through both a second-order Taylor expansion and a $(2,1)$ Padé approximant. We constrain the cosmographic parameters $(H_0,q_0,j_0)$ by combining Pantheon+ and SH0ES type Ia supernovae with gamma-ray bursts and then examine the impact of adding baryon acoustic oscillation measurements from the second DESI data release. The resulting constraints are used to construct a mock Sandage-Loeb catalog, after which the analyses are repeated including the simulated drift data. In this way, we assess the internal consistency of the reconstructed background rather than perform an independent forecast. Accordingly, we find that, for the SNeIa+GRB analysis, the Taylor reconstruction is compatible at the $1σ$ level with the $ω_0ω_1$CDM scenario, whereas the Padé parameterization improves the agreement of $q_0$ with the $Λ$CDM paradigm. Once DESI BAO data are included, the agreement with the reference background models weakens to the $2σ$ level. The addition of the mock Sandage-Loeb sample mainly tightens the bounds on $q_0$ and $j_0$, with moderate shifts in the central values. We finally compare the reconstructed redshift drift with the corresponding behavior predicted by the $Λ$CDM and $ω_0ω_1$CDM scenarios.
format Preprint
id arxiv_https___arxiv_org_abs_2604_03167
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Mapping the redshift drift at various redshifts through cosmography
Alfano, Anna Chiara
Luongo, Orlando
Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
The redshift drift provides a kinematic test of the cosmic expansion history through the slow time variation of the redshift of comoving sources. Motivated by the expected Sandage-Loeb measurements from future facilities, we investigate the drift within a cosmographic framework, modeling the Hubble rate through both a second-order Taylor expansion and a $(2,1)$ Padé approximant. We constrain the cosmographic parameters $(H_0,q_0,j_0)$ by combining Pantheon+ and SH0ES type Ia supernovae with gamma-ray bursts and then examine the impact of adding baryon acoustic oscillation measurements from the second DESI data release. The resulting constraints are used to construct a mock Sandage-Loeb catalog, after which the analyses are repeated including the simulated drift data. In this way, we assess the internal consistency of the reconstructed background rather than perform an independent forecast. Accordingly, we find that, for the SNeIa+GRB analysis, the Taylor reconstruction is compatible at the $1σ$ level with the $ω_0ω_1$CDM scenario, whereas the Padé parameterization improves the agreement of $q_0$ with the $Λ$CDM paradigm. Once DESI BAO data are included, the agreement with the reference background models weakens to the $2σ$ level. The addition of the mock Sandage-Loeb sample mainly tightens the bounds on $q_0$ and $j_0$, with moderate shifts in the central values. We finally compare the reconstructed redshift drift with the corresponding behavior predicted by the $Λ$CDM and $ω_0ω_1$CDM scenarios.
title Mapping the redshift drift at various redshifts through cosmography
topic Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2604.03167