An article published in “The Astrophysical Journal” reports some predictions offered by MOND (Modified Newtonian Dynamics), a theory based on modifications to Newton and Einstein’s gravitational laws that doesn’t include the existence of dark matter. Stacy S. McGaugh, James M. Schombert, Federico Lelli, and Jay Franck have applied this model to primordial galaxies studied with the James Webb Space Telescope obtaining a better agreement than the lambda-CDM model, the best cosmological model based on the existence of dark matter. This is one of the studies, often based on Webb’s observations, that are testing cosmological models that weren’t considered very much due to the lack of confirmation.
Since it was still in its design phase, the James Webb Space Telescope fueled the hopes of many scientists to obtain the data needed to make a leap forward in our understanding of the universe. The supporters of the lambda-CDM model hoped to obtain confirmations but almost three years after Webb’s launch, some results are bringing back to the fore MOND, a model that in the forty years from its first proposal enjoyed little consensus.
In recent years, some instruments led to the discovery of primordial massive galaxies that seem to have evolved at a speed much higher than possible according to the lambda-CDM model. The James Webb Space Telescope confirmed these discoveries and revealed more evolved primordial galaxies. Already in the 1990s, astrophysicist Bob Sanders predicted the presence of these galaxies using the MOND model.
Stacy S. McGaugh, James M. Schombert, and Federico Lelli, together with Tobias Mistele and Pengfei Li, had already published in “The Astrophysical Journal Letters” a study that offered further confirmations based on the MOND model to some galaxies’ rotation curves. The study involved an isolated sample of galaxies.
The new study is also far from comprehensive: for example, it included only a few hints at the beginning of the reionization period. This is a crucial period in the history of the universe, and the MOND model may offer better predictions of its beginning than the lambda-CDM model. However, further confirmation is needed again.
The authors of this study acknowledge the current limitations of the MOND model and the fact that the lambda-CDM model is in good agreement with various cosmological phenomena. Much more progress is needed to upend current theories of galaxy formation, but at best, the lambda-CDM model needs refinement.
Stacy S. McGaugh, the lead author of this study, who is involved in other studies of the MOND model, stated that finding a theory that is compatible with both MOND and general relativity is still a great challenge. In essence, the James Webb Space Telescope is providing a lot of new information about the early universe, but for now, it’s giving more questions than answers about some cosmological mysteries.
