Do any early JWST galaxies exceed the LCDM baryon budget?
In plain words
A galaxy cannot contain more stars than the total ordinary matter available in its dark matter halo. If some early galaxies break this rule, the standard cosmological model itself would be in trouble.
Precise statement
For a survey volume $V$ at redshift $z$, the most massive LCDM halo M_h,max(z, V) bounds the stellar mass by M_* <= f_b M_h,max with $f_b = \Omega_b / \Omega_m \sim 0.16$. Determine whether any galaxy with spectroscopic redshift and stellar mass corrected for active-galactic-nucleus light violates this bound.
What would settle it
Spectroscopic redshifts and dynamical or multi-band stellar masses for the most massive candidates at $z > 7$.
Status in the literature
Several early photometric massive candidates were revised downward after spectroscopy or reclassified as active nuclei; no confirmed violation is established.