Tensions in Cosmology: Interpreting Them Through Inhomogeneous Models
Abstract
We review a subset of the current tensions affecting the standard CDM 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 LTB 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 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 LTB 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.
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