Differing Manifestations of Spatial Curvature in Cosmological FRW Models

We found statistical evidence for a mismatch between the (global) spatial curvature parameter <i>K</i> in the geodesic equation for incoming photons and the corresponding parameter in the Friedmann equation that determines the time evolution of the background spacetime and its perturbati...

Full description

Saved in:
Bibliographic Details
Main Authors: Meir Shimon, Yoel Rephaeli
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Universe
Subjects:
Online Access:https://www.mdpi.com/2218-1997/11/5/143
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850256321844084736
author Meir Shimon
Yoel Rephaeli
author_facet Meir Shimon
Yoel Rephaeli
author_sort Meir Shimon
collection DOAJ
description We found statistical evidence for a mismatch between the (global) spatial curvature parameter <i>K</i> in the geodesic equation for incoming photons and the corresponding parameter in the Friedmann equation that determines the time evolution of the background spacetime and its perturbations. The mismatch, hereafter referred to as ‘curvature slip’, was especially evident when the SH0ES prior of the current expansion rate was assumed. This result is based on joint analyses of cosmic microwave background (CMB) observations with the PLANCK satellite (P18), the first year results of the Dark Energy Survey (DES), baryonic oscillation (BAO) data, and at a lower level of significance, the Pantheon SNIa (SN) catalog as well. For example, the betting odds against the null hypothesis were greater than <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mn>7</mn></msup></semantics></math></inline-formula>:1, 1400:1 and 1000:1 when P18+SH0ES, P18+DES+SH0ES and P18+BAO+SH0ES were considered, respectively. Datasets involving SNIa weakened this curvature slip considerably. Notably, even when the SH0ES prior was not imposed, the betting odds for the rejection of the null hypothesis were 70:1 and 160:1 in cases where P18+DES and P18+BAO were considered. When the SH0ES prior was imposed, the global fit of the modified model (that allows for a nonvanishing ‘curvature slip’) strongly outperformed that of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Λ</mo></semantics></math></inline-formula>CDM, being manifested by significant deviance information criterion (DIC) gains ranging between 7 and 23, depending on the dataset combination considered. Even in comparison with K<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Λ</mo></semantics></math></inline-formula>CDM, the proposed model resulted in significant, albeit smaller, DIC gains when SN data were excluded. Our finding could possibly be interpreted as an inherent inconsistency between the (idealized) maximally symmetric nature of the FRW metric and the dynamical evolution of the GR-based homogeneous and isotropic <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Λ</mo></semantics></math></inline-formula>CDM models. As such, this implies that there is apparent tension between the metric curvature and the curvature-like term in the time evolution of the redshift.
format Article
id doaj-art-eae1bbe5cd734bbeba30cebf687a793f
institution OA Journals
issn 2218-1997
language English
publishDate 2025-04-01
publisher MDPI AG
record_format Article
series Universe
spelling doaj-art-eae1bbe5cd734bbeba30cebf687a793f2025-08-20T01:56:39ZengMDPI AGUniverse2218-19972025-04-0111514310.3390/universe11050143Differing Manifestations of Spatial Curvature in Cosmological FRW ModelsMeir Shimon0Yoel Rephaeli1School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, IsraelSchool of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, IsraelWe found statistical evidence for a mismatch between the (global) spatial curvature parameter <i>K</i> in the geodesic equation for incoming photons and the corresponding parameter in the Friedmann equation that determines the time evolution of the background spacetime and its perturbations. The mismatch, hereafter referred to as ‘curvature slip’, was especially evident when the SH0ES prior of the current expansion rate was assumed. This result is based on joint analyses of cosmic microwave background (CMB) observations with the PLANCK satellite (P18), the first year results of the Dark Energy Survey (DES), baryonic oscillation (BAO) data, and at a lower level of significance, the Pantheon SNIa (SN) catalog as well. For example, the betting odds against the null hypothesis were greater than <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mn>7</mn></msup></semantics></math></inline-formula>:1, 1400:1 and 1000:1 when P18+SH0ES, P18+DES+SH0ES and P18+BAO+SH0ES were considered, respectively. Datasets involving SNIa weakened this curvature slip considerably. Notably, even when the SH0ES prior was not imposed, the betting odds for the rejection of the null hypothesis were 70:1 and 160:1 in cases where P18+DES and P18+BAO were considered. When the SH0ES prior was imposed, the global fit of the modified model (that allows for a nonvanishing ‘curvature slip’) strongly outperformed that of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Λ</mo></semantics></math></inline-formula>CDM, being manifested by significant deviance information criterion (DIC) gains ranging between 7 and 23, depending on the dataset combination considered. Even in comparison with K<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Λ</mo></semantics></math></inline-formula>CDM, the proposed model resulted in significant, albeit smaller, DIC gains when SN data were excluded. Our finding could possibly be interpreted as an inherent inconsistency between the (idealized) maximally symmetric nature of the FRW metric and the dynamical evolution of the GR-based homogeneous and isotropic <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Λ</mo></semantics></math></inline-formula>CDM models. As such, this implies that there is apparent tension between the metric curvature and the curvature-like term in the time evolution of the redshift.https://www.mdpi.com/2218-1997/11/5/143cosmologyspatial curvaturecurvature slipanomaly
spellingShingle Meir Shimon
Yoel Rephaeli
Differing Manifestations of Spatial Curvature in Cosmological FRW Models
Universe
cosmology
spatial curvature
curvature slip
anomaly
title Differing Manifestations of Spatial Curvature in Cosmological FRW Models
title_full Differing Manifestations of Spatial Curvature in Cosmological FRW Models
title_fullStr Differing Manifestations of Spatial Curvature in Cosmological FRW Models
title_full_unstemmed Differing Manifestations of Spatial Curvature in Cosmological FRW Models
title_short Differing Manifestations of Spatial Curvature in Cosmological FRW Models
title_sort differing manifestations of spatial curvature in cosmological frw models
topic cosmology
spatial curvature
curvature slip
anomaly
url https://www.mdpi.com/2218-1997/11/5/143
work_keys_str_mv AT meirshimon differingmanifestationsofspatialcurvatureincosmologicalfrwmodels
AT yoelrephaeli differingmanifestationsofspatialcurvatureincosmologicalfrwmodels