Re-evaluation of Ωk of the normalised Friedmann-Lemaître-Robertson-Walker model: Implications for Hubble constant determinations

• Published in: New astronomy 2021-10, Vol.88, p.101609, Article 101609
• Main Authors: Öztaş, Ahmet M., Smith, Michael L.
• Format: Article
• Language: English
• Subjects: (cosmology:) cosmological parameters; (cosmology:) early universe; 98.80.-k; 98.80.Bp; 98.80.Es; 98.80.Jk; Cosmology: theory
• ISSN: 1384-1076; 1384-1092; 1384-1092
• DOI: 10.1016/j.newast.2021.101609

•We suggest the current assignments of spacetime geometries to the Friedmann-Lemaitre-Robertson-Walker (FLRW) model are probably incorrect and suggest more useful descriptions.•This new assignment is consistent with our Universe exhibiting sparse matter density and quasi-Euclidean geometry and the calculated matter density agrees with Big Bang nucleosynthesis calculations.•Assigning a value of 1 for flat spacetime geometry to Friedmann’s normalised K is useful for estimating H0 and will help resolve the ”tension” surrounding current estimates by different investigators.•We extend the FLRW model towards the Big Bang and discover a simple explanation of how matter creation developed into the currently geometrically flat Universe with sparse, homogeneous, isotropic matter and energy distributions. The description of spacetime is an fundamental problem of cosmology. We explain why the current assignments of spacetime geometries for Ωk of the Friedmann-Lemaître-Robertson-Walker (FLRW) model are probably incorrect and suggest more useful descriptions. We show that Ωk represents not only curvature but the influence of matter density on the extent of spacetime between massive objects. Recent analyses of supernovae type Ia (SNe Ia) and HII/GEHR data with the FLRW model present the best fits with a small value for Ωm and a large Ωk. These results are consistent with our Universe exhibiting sparse matter density and quasi-Euclidean geometry and the small Ωm value agrees with Big Bang nucleosynthesis calculations. We suggest the geometry of our current Universe is better described by a value for Ωk≈1 rather than 0. As an example we extend the FLRW model towards the Big Bang and discover a simple explanation of how matter creation developed into the currently geometrically flat Universe with sparse, homogeneous, isotropic matter and energy distributions. Assigning Ωk≈1 to describe quasi-Euclidean spacetime geometry is also useful for estimating H0 and should help resolve the “tension” surrounding current estimates by different investigators.