High-Redshift Massive Galaxies at Cosmic Dawn: Testing Star Formation and Seed Black Holes
Early observations from the James Webb Space Telescope (JWST) in deep fields (JADES, CEERS, UNCOVER) discovered an unexpected population of luminous, massive galaxies at redshifts z = 10 to 14, within 300 to 450 million years of the Big Bang. Initial photometric estimations suggested stellar masses exceeding 10¹⁰ M☉, seemingly exhausting the total available baryonic reservoir in standard ΛCDM halos and challenging established star formation efficiency limits. Subsequent spectroscopic follow-up reveals that these "Universe Breakers" are driven by a combination of extreme dust-free starbursts with top-heavy initial mass functions and ubiquitous super-Eddington accreting primordial black holes ("Little Red Dots").