Cake Talk by Rajendra Gupta
Cosmic dawn observations of the James Webb Space Telescope (JWST) have revealed that the structure and masses of some of the very early Universe galaxies at high redshifts (𝑧~15) existing at ~0.3 Gyr after the BigBang are as evolved as the galaxies in existence for ~10 Gyr. Some JWST findings are thus in tension with the ΛCDM cosmological model, which predicts the age of the Universe as 13.8 Gyr. Efforts have been made with limited success to ease the tension by compressing the timeline for the formation of population III stars and galaxies, such as by considering the presence of primordial massive black hole seeds and super-Eddington accretion rates in the early Universe. Inspired by Dirac's hypothesis of the evolving gravitational constant, we have developed a GR-compliant expanding Universe model with the same number of free parameters as the ΛCDM model. The two parameters are determined by fitting the Pantheon+ supernovae type 1a data. The new model involves interrelated variations of multiple constants derived from local energy conservation. Combined with Zwicky's tired light concept, the new model eases the tension but almost doubles the age of the Universe. The covarying coupling constant (CCC) and tired light (TL) hybrid model yields the Universe's age at 𝑧=15 to be ~4.5 Gyr, thus giving adequate time for the galaxies to form and evolve as observed1. Recently, we have shown that the CCC+TL model is consistent with BAO observations at low redshifts as well as at the time of decoupling.