A Possible Solution to the Disagreement about the Hubble Constant

Recently the author [1] has proposed that a solution to the disagreement between the Planck collaboration CMB lower H₀ value, together with the BOSS collaboration BAO equally lower value, and the significantly higher value found by the SHOES collaboration cosmic distance ladder (CDL) study, arises from the CMB and BAO values being for a decelerating universe, rather than an accelerating universe. In contrast, the CDL H₀ is for an accelerating universe. To check , it is shown that when the deceleration parameter q₀ = - 0.55 in the CDL expression for H₀ is replaced by q₀ = 0.5 for the decelerating Einstein de Sitter (EdS) universe, CDL H₀ agrees with CMB and BAO values for z = 0.16, and z = 0.17, respectively. Earlier [2], it was shown that an EdS universe, with a dark energy that, instead of having a negative pressure, has a non-dispersive index of refraction n ≈1.5, for 0 ≤ z ≤ 0.6, so that the speed of light through intergalactic, but not galactic, space is ~2c/3, yields an alternative explanation for the increased apparent magnitude of the SNe Ia, and increased distance to the BAO "standard ruler." An astronomical test based on discordant redshifts has been proposed [3].

¹ F. R. Tangherlini, J. Mod. Phys., 9, 1827 (2018); ² 6, 78 (2015); ³ 8, 622 (2017).