The Hubble Law: Its Relational Justification and the Hubble Tension

In the recent years, a number of studies have been carried out to substantiate cosmological effects within the framework of the relational approach to the nature of space-time and physical interactions. It has been shown that the cosmological redshift and the cosmic microwave background can be a result of contributions from emitted but unabsorbed radiation. However, until now, Hubble’s law has not been entirely derived from the relational ideas themselves. In this paper, such a derivation is presented, and the Hubble parameter is calculated for the present epoch. To get this, the momentum contributions of emitted but unabsorbed radiation to the momentum of a distant astronomical object (a cluster of galaxies) are considered. It is shown that taking these contributions into account leads to the linear Hubble law.