In a recent study of his, the researcher points out that the most massive galaxy candidates featured in JWST observations appear to be “at the very edge” of the number and stellar mass density limits set by the existing Lambda cold dark matter cosmological model.
In layman’s terms, the galaxies, which are estimated to be seen by astronomers about 500-700 million years after the Big Bang, appear to be much more massive than they should be if the aforementioned cosmological model is correct.
“If the masses are right, then we are in uncharted territory,” Boylan-Kolchin said as quoted in a press release by the UT.
“We’ll require something very new about galaxy formation or a modification to cosmology,” he added. “One of the most extreme possibilities is that the universe was expanding faster shortly after the Big Bang than we predict, which might require new forces and particles.”
The press release does point out, however, that the galaxies’ parameters are merely “initial estimates” that should be confirmed via spectroscopy, and that these galaxies may turn out to be smaller than originally anticipated.