Testing inhomogeneous cosmography in our cosmic neighborhood using CosmicFlows-4

Abstract

The convergence of the third order general cosmographic expansion of the luminosity distance is examined using several versions of a semi-realistic model of our local cosmic neighborhood, based on publicly available density and velocity fields from CosmicFlows-4. The study supports earlier findings that the general cosmographic expansion diverges at surprisingly low redshifts, often well before z = 0.1. By being based on a realistically placed observer within a data-informed cosmic environment, the results underscore that convergence must be a central concern when applying the general cosmographic expansion. By showing all-sky maps of kinematic parameters, the study also highlights the substantial information we lose when relying solely on standard FLRW-based cosmography. Poor convergence does not necessarily render the information extracted by fitting data to the general cosmographic expansion meaningless. Rather, it calls for caution in interpreting this information, particularly regarding the physical meaning of the fitting coefficients, the physical scales they probe and the implicit smoothing introduced by the fit.

Submitted to PRD. v2: Analysis significantly extended but no changes in overall conclusions. 21 pages. Matches version accepted for publication in PRD. v3: Minor clarifying note (footnote 2) added after publication. No changes to results or conclusions

References in corpus (22)

• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• The Hubble series: Convergence properties and redshift variables
• A Challenge to the Standard Cosmological Model
• Cosmicflows-4
• Analyzing the Large-Scale Bulk Flow using CosmicFlows4: Increasing Tension with the Standard Cosmological Model
• The peculiar velocity field up to $z\sim 0.05$ by forward-modeling Cosmicflows-3 data
• Anti-lensing: the bright side of voids
• Testing the Cosmological Principle with CatWISE Quasars: A Bayesian Analysis of the Number-Count Dipole
• The cosmic radio dipole: Bayesian estimators on new and old radio surveys
• Gravity in the Local Universe : density and velocity fields using CosmicFlows-4
• Identification of Basins of Attraction in the Local Universe
• Covariant cosmography: the observer-dependence of the Hubble parameter
• Testing the isotropy of cosmic acceleration with Pantheon+ and SH0ES: A cosmographic analysis
• Testing cosmic anisotropy with Pade approximation and Pantheon+ sample
• Cosmography of the Local Universe by Multipole Analysis of the Expansion Rate Fluctuation Field
• Consistency of Pantheon+ supernovae with a large-scale isotropic universe
• Cosmological distances with general-relativistic ray tracing: framework and comparison to cosmographic predictions
• Towards Cosmography of the Local Universe
• Expanding covariant cosmography of the local Universe: incorporating the snap and axial symmetry
• On the convergence of cosmographic expansions in Lemaitre-Tolman-Bondi models
• Anisotropy in the cosmic acceleration inferred from supernovae

Cited by in corpus (3)

• Backreaction and the Role of Spatial Curvature in the Cosmic Neighborhood
• An effective $\mathbf{\Lambda }$-Szekeres modelling of the local Universe with Cosmicflows-4
• Testing the cosmological principle on gigaparsec scales