A new null test is proposed to isolate cosmologies with non-FLRW observational relations by characterizing how they violate curvature-consistency tests of the standard FLRW framework.
R¨ as¨ anen, K
4 Pith papers cite this work. Polarity classification is still indexing.
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abstract
We present a new test of the validity of the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric, based on comparing the distance from redshift 0 to $z_1$ and from $z_1$ to $z_2$ to the distance from $0$ to $z_2$. If the universe is described by the FLRW metric, the comparison provides a model-independent measurement of spatial curvature. The test relies on geometrical optics, it is independent of the matter content of the universe and the applicability of the Einstein equation on cosmological scales. We apply the test to observations, using the Union2.1 compilation of supernova distances and Sloan Lens ACS Survey galaxy strong lensing data. The FLRW metric is consistent with the data, and the spatial curvature parameter is constrained to be $-1.22<\Omega_{K0}<0.63$, or $-0.08<\Omega_{K0}<0.97$ with a prior from the cosmic microwave background and the local Hubble constant, though modelling of the lenses is a source of significant systematic uncertainty.
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astro-ph.CO 4years
2026 4representative citing papers
Bootstrap symbolic regression of SN+BAO data yields mild 2–4σ FLRW consistency deviations and a density field still compatible with both Planck and SH0ES ΛCDM.
Combining GWTC-4 standard sirens with TDCOSMO2025 lensing data under the distance sum rule yields H0 = 83.78 +12.53/-10.23 km/s/Mpc (13.6% precision) in one configuration, consistent with both Planck and SH0ES.
Gaia quasar proper motions show a significant quadrupole signal matching an axisymmetric Bianchi I anisotropy model, but the amplitude does not increase with redshift as the model requires and the inferred local shear exceeds expectations.
citing papers explorer
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Observational Tests for Distinguishing Classes of Cosmological Models
A new null test is proposed to isolate cosmologies with non-FLRW observational relations by characterizing how they violate curvature-consistency tests of the standard FLRW framework.
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Model-independent constraints on generalized FLRW consistency relations with bootstrap-based symbolic regression
Bootstrap symbolic regression of SN+BAO data yields mild 2–4σ FLRW consistency deviations and a density field still compatible with both Planck and SH0ES ΛCDM.
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Model-independent H0 from GWTC-4 standard sirens and TDCOSMO 2025 strong lensing time delays
Combining GWTC-4 standard sirens with TDCOSMO2025 lensing data under the distance sum rule yields H0 = 83.78 +12.53/-10.23 km/s/Mpc (13.6% precision) in one configuration, consistent with both Planck and SH0ES.
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Mapping the Universe as a Bianchi I cosmology with Gaia data
Gaia quasar proper motions show a significant quadrupole signal matching an axisymmetric Bianchi I anisotropy model, but the amplitude does not increase with redshift as the model requires and the inferred local shear exceeds expectations.