Easing the Hubble constant tension?

Abstract

We show how a modified Friedmann equation, originating from a model of the universe built from a certain W 3 algebra, has the potential to explain the difference between the Hubble constants extracted from CMB data and from supernova data.

The large scale structure of the Universe from a modified Friedmann equation

“…As noticed in [2] the situation is the same in our model: our "effective" w(z) < −1 (and approaches −1 for late times), and the purpose of this article is to show that for precisely the same values of our baby universe parameter B which ease the H 0 tension, we also agree with a number of other late time cosmological observations while assuming the same physics as the Planck Collaboration at and before the time of last scattering (we denote this physics CMB physics).…”

“…The reason we consider this third model, denoted SC for "standard candles" used to measure distances for small z, is that it is the ΛCDM model where H(z) is calculated using precisely the same assumptions as for our baby universe model. 2 The data points are from Table 1 in the Appendix and lead to reduced χ 2 values 3 (χ…”

“…In previous articles [1,2] we have advocated a modified Friedmann equation which is able to resolve the H 0 tension and where the cosmological constant is assumed to be zero at present time due to Coleman's mechanism [3]. The modified Friedmann equation arose from a "model of the Universe" suggested in [4].…”

Models of the universe based on Jordan algebras

“…( 20) is used to express p in terms of ȧ/a. In [12,13,14] we studied this Friedmann equation for f (p) given by (19) and called it the modified Friedmann equation. We will restrict ourselves to that case in the following, and one can then integrate (21) analytically to find…”