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The recent discovery of objects with redshift $z>10$ with the help of JamesWebb Space Telescope (JWST) poses serious challenges to the $\Lambda$CDMcosmological model, which has been in vogue for some time now. The new dataindicate that galaxy formation must have taken place much earlier than expectedin this model. Another viable class of cosmological models is that of theso-called coasting models, in which the scale factor of the universe variesproportionately with time. In these models, the universe at redshift $z=12$ hasample time ($\sim 1070$ Myrs) for galaxy formation. The earliest such model isthe one proposed by E.A. Milne, based on his `kinematic relativity', but it isconsidered unrealistic for not treating gravity as relevant at cosmologicalscales. A closed version of an eternal coasting FLRW model was proposed by thepresent authors even before SNe Ia data began to pour in. Subsequently wedeveloped a more general model of the same class, which is valid for all thethree possible geometries, with open, closed or flat spatial sections. In thenonrelativistic era, this model makes the falsifiable prediction that the ratioof matter density to dark energy density is 2. This avoids the cosmiccoincidence problem. Moreover, this eternal coasting model allows room forcreation of matter from dark energy, that may speed up galaxy and structureformation at the early epochs, as implied by the JWST data. The paper alsoattempts to review some similar coasting models, but emphasizes the eternalcoasting cosmology as the most probable candidate model capable of explainingthe presence of high redshift galaxies discovered by JWST.

Cosmological significance of the early bright galaxies observed with JWST