Hubble parameter and related formulas for a Weyl scaling invariant dark energy action

Abstract

We derive a compact formula for the squared Hubble parameter versus redshift corresponding to a Weyl scaling invariant dark energy action. It involves effective dark energy and matter densities that both differ from their expressions in standard $\Lambda CDM$ cosmologies. The modified densities are given by explicit formulas expressed in terms of the one initial state parameter $\Phi(0)$ of the model. Numerical values corresponding to choosing $\Phi(0)$ to resolve the Hubble tension are summarized in tabular form.