English

Tensions in Cosmology: Interpreting Them Through Inhomogeneous Models

Cosmology and Nongalactic Astrophysics 2026-02-02 v1

Abstract

We review a subset of the current tensions affecting the standard Λ\LambdaCDM cosmological model, emphasizing the role of chronic systematics and significance inflation in shaping their interpretation. As a unifying framework, we consider the spherically symmetric inhomogeneous Λ\LambdaLTB model and use it as a set of "glasses" through which to reinterpret the Hubble, dipole, and dark-energy tensions. Large-scale spatial gradients in this model introduce anisotropic expansion and position-dependent observables, allowing local estimates of H0H_{0} to shift, dipolar signatures to arise, and an apparently evolving dark-energy equation of state to be mimicked without invoking genuinely dynamical dark energy. We discuss how these effects are constrained once the full supernova, CMB, and large-scale-structure data sets are included, and argue that it remains unclear whether any single Λ\LambdaLTB configuration can simultaneously account for all major anomalies. More broadly, we highlight that cosmology currently lacks a widely accepted baseline model that is both theoretically well founded and capable of accommodating the Hubble and dark-energy tensions, leaving us without a true concordance framework for forecasting future surveys.

Keywords

Cite

@article{arxiv.2601.22278,
  title  = {Tensions in Cosmology: Interpreting Them Through Inhomogeneous Models},
  author = {Valerio Marra},
  journal= {arXiv preprint arXiv:2601.22278},
  year   = {2026}
}

Comments

To appear in the Proceedings of the XLVIII Annual Meeting of the Brazilian Astronomical Society

R2 v1 2026-07-01T09:26:38.734Z