JWST early Universe observations and ΛCDM cosmology

Abstract

Deep space observations of the James Webb Space Telescope (JWST) have revealed that the structure and masses of very early Universe galaxies at high redshifts ($z\sim 15$), existing at $\sim $0.3 Gyr after the BigBang, may be as evolved as the galaxies in existence for $\sim 10$ Gyr. The JWST findings are thus in strong tension with the ${\rm{\Lambda }}$CDM cosmological model. While tired light (TL) models have been shown to comply with the JWST angular galaxy size data, they cannot satisfactorily explain isotropy of the cosmic microwave background (CMB) observations or fit the supernovae distance modulus vs. redshift data well. We have developed hybrid models that include the tired light concept in the expanding universe. The hybrid ${\rm{\Lambda }}$CDM model fits the supernovae type 1a data well but not the JWST observations. We present a model with covarying coupling constants (CCC), starting from the modified FLRW metric and resulting Einstein and Friedmann equations, and a CCC + TL hybrid model. They fit the Pantheon + data admirably, and the CCC + TL model is compliant with the JWST observations. It stretches the age of the universe to 26.7 Gyr with 5.8 Gyr at $z\,\, = \,\,10$ and 3.5 Gyr at $z\,\, = \,\,20$, giving enough time to form massive galaxies. It thus resolves the ‘impossible early galaxy’ problem without requiring the existence of primordial black hole seeds or modified power spectrum, rapid formation of massive population III stars, and super Eddington accretion rates. One could infer the CCC model as an extension of the ${\rm{\Lambda }}$CDM model with a dynamic cosmological constant.

Novel Cosmological Joint Constraints in Multidimensional Observable Space with Redshift-free Inferences

“…The ΛCDM model is largely only well tested at low redshifts z  1 and at very high redshifts z ∼ 1100. A recent article using JWST's high-redshift observations (z ∼ 15) indicates that there is a great tension between the JWST results and the ΛCDM model (Gupta 2023). In conclusion, our method can make an attempt in this matter, especially after determining the variation of cosmological information in the reconstruction methodology.…”

Galaxy rotation curve in hyperconical universes: a natural relativistic MOND

“…In fact, the linear expansion (e.g. R h = ct model) better predicts the formation of highredshift galaxies than the standard ΛCDM [62], which is statistically incompatible to model the known as 'impossible early galaxies' [63][64][65].…”

Testing CCC+TL Cosmology with Observed Baryon Acoustic Oscillation Features

“…We now need to transpose f (t) to f (z), as it is the latter that we will require in calculating the proper distance. Following Gupta's (2023) Equations ( 24)-( 27), we have…”

“…We can now follow TL and CCC+TL models developed by Gupta (2023) for our computations in this work. Sound Horizon Distance and Angular Size.…”

“…Their work was extended to include observations that provided θ BAO at z = 0.11 within z = [0.105, 0.115] (Carvalho et al 2021), and at up to z = 0.65 (Lemos et al 2023). We will use their data to explore if the recently proposed hybrid model (Gupta 2023) is consistent with features of the BAOs observed in the CMB and matter power spectra. This model comprises a modified ΛCDM model permitting the covariation of coupling constants (CCC) and includes the tired light (TL) phenomenon to partially account for the observed redshift.…”