Apparent Dark-Energy Evolution from Cosmic Inhomogeneities

Fuente: arXiv
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Hauptverfasser: Ginat, Yonadav Barry, Ferreira, Pedro G.
Format: Preprint
Veröffentlicht: 2026
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author Ginat, Yonadav Barry
Ferreira, Pedro G.
author_facet Ginat, Yonadav Barry
Ferreira, Pedro G.
contents A mildly inhomogeneous universe with a cosmological constant may look like it contains evolving dark energy. We show that could be the case by modelling the inhomogeneities and their effects in three different ways: as clumped matter surrounded by voids, as back-reaction of small-scale structure on the overall expansion of the Universe, and, finally, as a large-scale curvature inhomogeneity. In all of these cases, the propagation of light is affected, and differs from that in a homogeneous and isotropic universe. The net result is that cosmological observables, such as angular diameter and luminosity distances, become distorted. We find, in all three models, that the inclusion of these effects pushes the distance-redshift relation towards closer agreement with recent data from both supernovae Ia from the Dark Energy Survey, and from baryon acoustic oscillations from the Dark Energy Spectroscopic Instrument. The amount of inhomogeneity in these models might not be enough to explain the entirety of the deviation from a cosmological constant, but is found to be of a similar order of magnitude, hinting that these data may be consistent with a universe dominated by a cosmological constant.
format Preprint
id arxiv_https___arxiv_org_abs_2601_20633
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Apparent Dark-Energy Evolution from Cosmic Inhomogeneities
Ginat, Yonadav Barry
Ferreira, Pedro G.
Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
A mildly inhomogeneous universe with a cosmological constant may look like it contains evolving dark energy. We show that could be the case by modelling the inhomogeneities and their effects in three different ways: as clumped matter surrounded by voids, as back-reaction of small-scale structure on the overall expansion of the Universe, and, finally, as a large-scale curvature inhomogeneity. In all of these cases, the propagation of light is affected, and differs from that in a homogeneous and isotropic universe. The net result is that cosmological observables, such as angular diameter and luminosity distances, become distorted. We find, in all three models, that the inclusion of these effects pushes the distance-redshift relation towards closer agreement with recent data from both supernovae Ia from the Dark Energy Survey, and from baryon acoustic oscillations from the Dark Energy Spectroscopic Instrument. The amount of inhomogeneity in these models might not be enough to explain the entirety of the deviation from a cosmological constant, but is found to be of a similar order of magnitude, hinting that these data may be consistent with a universe dominated by a cosmological constant.
title Apparent Dark-Energy Evolution from Cosmic Inhomogeneities
topic Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2601.20633