Soft quantum back reaction to the Hubble tension: a smeared-out early time cosmological energy density

A theoretical explanation for the so-called Hubble tension is provided within the framework of phase-space quantum mechanics extended to (quantum) cosmology. Following a description of the overall nature of this tension, with due attention to recent observational developments, a quantum cosmology framework based on the Weyl-Wigner phase-space quantum approach is presented. This circumvents the discrepancy between early- and late-time Universe predictions for the Hubble constant, $H_0$. The emergence of quantum-origin corrections dependent on a single parameter – mediated by (generic) localized phase-space quantum states free of data analysis – yields predictions for $H_0$ that smoothly interpolate between early- and late-time phenomenological values, thereby joining the plethora of solutions for the Hubble tension.