Data from DR17 of the SDSS in the g, i, r, u, z bands were used to compute galaxy number counts and galaxy density per square degree in the composite bJ band over two areas of sky centred on the North Galactic Cap (NGC) and above the South Galactic Cap (SGC), with areas of 5,954 and 859 sq. deg. respectively and a combined count of 622,121 galaxies within the limits of redshift ≤0.4 and bJ≤20. The comparative densities confirmed an extensive void in the Southern sky with a deficit of 26% out to a redshift z∼0.15. Number counts in the K−, R−, I−, H−, B− and U−bands were derived from the Durham Extragalactic Astronomy and Cosmology catalogue and were well fitted to a general relativity (GR) cosmological model over their whole range, requiring only modest luminosity evolution, except for a steeper curve in the B−band at faint magnitudes required a star-burst evolutionary model to account for the excess faint number counts. Extending the SDSS redshift-number count survey to fainter and more distant galaxies with redshift ≤1.20 and bJ≤24 showed a secondary peak in the number counts that may account for this observed apparent excess of faint blue galaxy counts. Individual examination of a sample of these galaxies suggested that many were QSOs, bright X-ray or radio sources, or evolving irregular galaxies with rapid star formation rates. This sub-population at redshifts 0.45−0.65 may account for the excess counts observed in the B− optical band.

Hubble expansion may be considered as a velocity per photon travel time rather than as velocity or redshift per distance. Dimensionally, this is an acceleration and will have an associated curvature of space under general relativity. This paper explores this theoretical curvature as an extension to the spacetime manifold of general relativity, generating a modified solution with three additional non-zero Christoffel symbols, and a reformulated Ricci tensor and curvature. The observational consequences of this reformulation were compared with the ΛCDM model for luminosity distance using the extensive type Ia supernovae (SNe Ia) data with redshift corrected to the CMB, and for angular diameter distance with the recent baryonic acoustic oscillation (BAO) data. For the SNe Ia data, the modified GR and ΛCDM models differed by −0.15+0.11μB mag. over zcmb=0.01−1.3, with overall weighted RMS errors of ±0.136μB mag for modified GR and ±0.151μB mag for ΛCDM espectively. The BAO measures spanned a range z=0.106−2.36, with weighted RMS errors of ±0.034 Mpc with H0=67.6±0.25 for the modified GR model, and ±0.085 Mpc with H0=70.0±0.25 for the ΛCDM model. The derived GR metric for this new solution describes both the SNe Ia and the BAO observations with comparable accuracy to ΛCDM without requiring the inclusion of dark matter or w’-corrected dark energy.