The Emperor's New Arc: gigaparsec patterns abound in a $Λ$CDM universe

Fuente: arXiv
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Main Authors: Sawala, Till, Teeriaho, Meri, Frenk, Carlos S., Helly, John, Jenkins, Adrian, Racz, Gabor, Schaller, Matthieu, Schaye, Joop
Format: Preprint
Published: 2025
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author Sawala, Till
Teeriaho, Meri
Frenk, Carlos S.
Helly, John
Jenkins, Adrian
Racz, Gabor
Schaller, Matthieu
Schaye, Joop
author_facet Sawala, Till
Teeriaho, Meri
Frenk, Carlos S.
Helly, John
Jenkins, Adrian
Racz, Gabor
Schaller, Matthieu
Schaye, Joop
contents Recent discoveries of apparent large-scale features in the structure of the universe, extending over many hundreds of megaparsecs, have been claimed to contradict the large-scale isotropy and homogeneity foundational to the standard ($Λ$CDM) cosmological model. We explicitly test and refute this conjecture using FLAMINGO-10K, a new and very large cosmological simulation of the growth of structure in a $Λ$CDM context. Applying the same methods used in the observations, we show that patterns like the "Giant Arc", supposedly in tension with the standard model, are, in fact, common and expected in a $Λ$CDM universe. We also show that their reported significant overdensities are an algorithmic artefact and unlikely to reflect any underlying structure.
format Preprint
id arxiv_https___arxiv_org_abs_2502_03515
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The Emperor's New Arc: gigaparsec patterns abound in a $Λ$CDM universe
Sawala, Till
Teeriaho, Meri
Frenk, Carlos S.
Helly, John
Jenkins, Adrian
Racz, Gabor
Schaller, Matthieu
Schaye, Joop
Cosmology and Nongalactic Astrophysics
Recent discoveries of apparent large-scale features in the structure of the universe, extending over many hundreds of megaparsecs, have been claimed to contradict the large-scale isotropy and homogeneity foundational to the standard ($Λ$CDM) cosmological model. We explicitly test and refute this conjecture using FLAMINGO-10K, a new and very large cosmological simulation of the growth of structure in a $Λ$CDM context. Applying the same methods used in the observations, we show that patterns like the "Giant Arc", supposedly in tension with the standard model, are, in fact, common and expected in a $Λ$CDM universe. We also show that their reported significant overdensities are an algorithmic artefact and unlikely to reflect any underlying structure.
title The Emperor's New Arc: gigaparsec patterns abound in a $Λ$CDM universe
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2502.03515