A recent analysis by cosmologist Dr. Jenny Wagner, featured on the podcast Theories of Everything with Curt Jaimungal, suggests that data from the James Webb Space Telescope has challenged what many considered a 'smoking gun' for dark matter.
The finding centers on the so-called 'inverse problem' in astrophysics: multiple possible distributions of dark matter can produce the same observable gravitational effects, making it difficult to pinpoint a unique model. According to Wagner, new JWST observations of early galaxies and gravitational lensing are narrowing down possibilities, but they have also shown that previous candidate signals could be explained by modified gravity theories as well.
"The JWST data is so precise that it's ruling out many dark matter models that were previously favored," Wagner said. "But it hasn't yet provided the unambiguous proof we were hoping for."
The discussion highlights how the telescope is reshaping cosmology, forcing scientists to reconsider long-held assumptions about dark matter's role in galaxy formation.
Wagner's work underscores that while dark matter remains the dominant paradigm, alternative theories like Modified Newtonian Dynamics (MOND) may still be viable. The JWST, far from settling the debate, has opened new questions about the fundamental nature of the universe.