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pinball1970
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- TL;DR Summary
- The standard model for how galaxies formed in the early universe predicted that the James Webb Space Telescope would see dim signals from small, primitive galaxies. But data are not confirming the popular hypothesis that invisible dark matter helped the earliest stars and galaxies clump together.
"What the theory of dark matter predicted is not what we see," said Case Western Reserve astrophysicist Stacy McGaugh, whose paper (12.11.24) describes structure formation in the early universe.
McGaugh, professor and director of astronomy at Case Western Reserve, said instead of dark matter, modified gravity might have played a role. He says a theory known as MOND, for Modified Newtonian Dynamics, predicted in 1998 that structure formation in the early universe would have happened very quickly—much faster than the theory of Cold Dark Matter, known as lambda-CDM, predicted.
https://iopscience.iop.org/article/10.3847/1538-4357/ad834d (open access)
There was also this in Nature (abstract only)
https://www.nature.com/articles/s41586-024-08094-5 (13.11.24)
A survey of 36 galaxies that yielded "three ultra-massive galaxies (logM★/M⊙ ≳ 11.0, where M★ is the stellar mass and M⊙ is the mass of the Sun) require an exceptional fraction of 50 per cent of baryons converted into stars—two to three times higher than the most efficient galaxies at later epochs."
and "The contribution from an active galactic nucleus is unlikely because of their extended emission."
Possibly a reference a couple of studies like the below in the last few months,
https://iopscience.iop.org/article/10.3847/1538-3881/ad57c1
McGaugh, professor and director of astronomy at Case Western Reserve, said instead of dark matter, modified gravity might have played a role. He says a theory known as MOND, for Modified Newtonian Dynamics, predicted in 1998 that structure formation in the early universe would have happened very quickly—much faster than the theory of Cold Dark Matter, known as lambda-CDM, predicted.
https://iopscience.iop.org/article/10.3847/1538-4357/ad834d (open access)
There was also this in Nature (abstract only)
https://www.nature.com/articles/s41586-024-08094-5 (13.11.24)
A survey of 36 galaxies that yielded "three ultra-massive galaxies (logM★/M⊙ ≳ 11.0, where M★ is the stellar mass and M⊙ is the mass of the Sun) require an exceptional fraction of 50 per cent of baryons converted into stars—two to three times higher than the most efficient galaxies at later epochs."
and "The contribution from an active galactic nucleus is unlikely because of their extended emission."
Possibly a reference a couple of studies like the below in the last few months,
https://iopscience.iop.org/article/10.3847/1538-3881/ad57c1