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Bibliographic Details
Main Authors: Zhou, Alan Junzhe, Dodelson, Scott, Scolnic, Daniel
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2506.14878
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author Zhou, Alan Junzhe
Dodelson, Scott
Scolnic, Daniel
author_facet Zhou, Alan Junzhe
Dodelson, Scott
Scolnic, Daniel
contents We test the isotropy of Hubble expansion by combining several probes for the first time, constructing full-sky maps of expansion rate variation using Type Ia supernovae, fundamental plane galaxies, and CMB temperature fluctuations. We find no hint of anisotropy or correlation between early- and late-Universe expansion across all systematic models. The 99% confidence upper limits on expansion rate anisotropy are 0.39% for low-redshift supernovae, 0.95% for high-redshift CMB, and 0.37% when combined at a 60-degree smoothing scale. A significant anomaly in the fundamental plane residual map may reflect systematics in the current DESI dataset, as evidenced by the absence of cross-correlation with other tracers and its correlation with spatial density variations.
format Preprint
id arxiv_https___arxiv_org_abs_2506_14878
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The isotropy of Hubble expansion in the early and late Universe
Zhou, Alan Junzhe
Dodelson, Scott
Scolnic, Daniel
Cosmology and Nongalactic Astrophysics
Astrophysics of Galaxies
We test the isotropy of Hubble expansion by combining several probes for the first time, constructing full-sky maps of expansion rate variation using Type Ia supernovae, fundamental plane galaxies, and CMB temperature fluctuations. We find no hint of anisotropy or correlation between early- and late-Universe expansion across all systematic models. The 99% confidence upper limits on expansion rate anisotropy are 0.39% for low-redshift supernovae, 0.95% for high-redshift CMB, and 0.37% when combined at a 60-degree smoothing scale. A significant anomaly in the fundamental plane residual map may reflect systematics in the current DESI dataset, as evidenced by the absence of cross-correlation with other tracers and its correlation with spatial density variations.
title The isotropy of Hubble expansion in the early and late Universe
topic Cosmology and Nongalactic Astrophysics
Astrophysics of Galaxies
url https://arxiv.org/abs/2506.14878