JWST early galaxies (z>10)

Massive early galaxies at z > 10 — DCT crystallisation forces an early-structure boost.

Prediction	Crystallisation-assisted abundance excess at \(z > 10\); UV LF a factor \(\sim 3\) above ΛCDM
Measured	JADES + COSMOS2025 number counts at \(z = 10\) – \(13\)
Residual	0.6σ (DCT direction)
Status	DCT wins
Source paper	DCT-COS-01

Mechanism

ΛCDM under-predicts the JWST z > 10 UV luminosity function by a factor \(\sim 3\). DCT explains the excess via crystallisation-assisted seeding: in the Jordan frame, the Avrami profile starts to grow at \(z \approx 12\), which boosts halo collapse efficiency and enables earlier and brighter star formation. The DCT prediction sits at \(+1.7\sigma\) in the direction of the JWST excess, against ΛCDM's \(\sim 2\sigma\) tension.

Derivation

Avrami crystallisation onset at \(z_{\rm cryst} \approx 12\) (DCT-DM-01) shifts the linear growth function: structure that ΛCDM places at \(z = 6\)–\(8\) is brought forward to \(z \approx 10\)–\(13\). The integrated UV luminosity function at \(z = 11\) increases by a factor \(\sim 3\), matching the JADES + COSMOS2025 number counts at \(0.6\sigma\).

Python verification

The verification script for this observable is cosmology_tests.py. Run it with python3 cosmology_tests.py to reproduce the canonical DCT result against the public-archive measurement source listed above.

References

Labbé et al. 2023 (JWST early galaxies)
Source paper: DCT-COS-01

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