%0 Journal Article %A Hujeirat, Ahmad %C Heidelberg %D 2023 %F heidok:32887 %I Universität %K General Relativity: big bang, black holes, quasars, neutron stars, quantum chromodynamics, condensed matter, incompressibility, superfluidity, super-conductivity %P 1-18 %R 10.11588/heidok.00032887 %T Hubble tension versus the cosmic evolution of Hubble parameter in the unicentric model of the observable universe %U https://archiv.ub.uni-heidelberg.de/volltextserver/32887/ %X Recently, a unicentric model of the observable universe was proposed. Accordingly, big bangs are frequent events in our infinitely large, flat, homogeneous and isotropic parent universe. Their progenitors are clusters of cosmically dead and massive neutron stars that merged after reaching the ultimate lowest quantum energy state, where the matter is in an incompressible superconducting gluon-quark superfluid state and zero-entropy. The resulting progenitors are of measurable sizes and immune to collapsing into black holes. Our big bang's progenitor accidentally happened to take off in our neighbourhood. As the enclosed mass of the progenitor was finite, the dynamically expanding curved spacetimes embedded the fireball started flattening to finally diffuse into the flat spacetime of the parent universe. By means of GR-numerical hydrodynamical calculations, we use the H−metric to follow the time-evolution of the spacetime embedding the progenitor during the hadronization phase and thereafter. Based thereon, we find that the kinetic energy of newly created normal matter increases with distance in a self-similar manner, imitating thereby outflows of nearly non-interacting particles. On cosmic time scales, this behaviour yields a Hubble parameter, H(t), which decreases slowly with the distance from the big bang event. Given the sensitivity of the CMB-Planck data to the underlying cosmological model, we conclude that our unicentric model of the universe is a viable alternative to ΛCMD-cosmologies.