A cosmic glitch in gravity

Fuente: arXiv
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Autores principales: Wen, Robin Y., Hergt, Lukas T., Afshordi, Niayesh, Scott, Douglas
Formato: Preprint
Publicado: 2023
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author Wen, Robin Y.
Hergt, Lukas T.
Afshordi, Niayesh
Scott, Douglas
author_facet Wen, Robin Y.
Hergt, Lukas T.
Afshordi, Niayesh
Scott, Douglas
contents We investigate a model that modifies general relativity on cosmological scales, specifically by having a `glitch' in the gravitational constant between the cosmological (super-horizon) and Newtonian (sub-horizon) regimes, as motivated e.g. in the Hořava-Lifshitz proposal or in the Einstein-aether framework. This gives a single-parameter extension to the standard $Λ$CDM model, which is equivalent to adding a dark energy component, but where the energy density of this component can have either sign. Fitting to data from the Planck satellite, we find that negative contributions are, in fact, preferred. Additionally, we find that roughly one percent weaker superhorizon gravity can somewhat ease the Hubble and clustering tensions in a range of cosmological observations, although at the expense of spoiling fits to the baryonic acoustic oscillation scale in galaxy surveys. Therefore, the extra parametric freedom offered by our model deserves further exploration, and we discuss how future observations may elucidate this potential cosmic glitch in gravity, through a four-fold reduction in statistical uncertainties.
format Preprint
id arxiv_https___arxiv_org_abs_2311_03028
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A cosmic glitch in gravity
Wen, Robin Y.
Hergt, Lukas T.
Afshordi, Niayesh
Scott, Douglas
Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
We investigate a model that modifies general relativity on cosmological scales, specifically by having a `glitch' in the gravitational constant between the cosmological (super-horizon) and Newtonian (sub-horizon) regimes, as motivated e.g. in the Hořava-Lifshitz proposal or in the Einstein-aether framework. This gives a single-parameter extension to the standard $Λ$CDM model, which is equivalent to adding a dark energy component, but where the energy density of this component can have either sign. Fitting to data from the Planck satellite, we find that negative contributions are, in fact, preferred. Additionally, we find that roughly one percent weaker superhorizon gravity can somewhat ease the Hubble and clustering tensions in a range of cosmological observations, although at the expense of spoiling fits to the baryonic acoustic oscillation scale in galaxy surveys. Therefore, the extra parametric freedom offered by our model deserves further exploration, and we discuss how future observations may elucidate this potential cosmic glitch in gravity, through a four-fold reduction in statistical uncertainties.
title A cosmic glitch in gravity
topic Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2311.03028