>Empirical Appendix: Scaling Deviations and Saturation Thresholds v2

Empirical Appendix: Scaling Deviations and Saturation Thresholds

This appendix should be read in conjunction with §2.1 (RST as a Corrective Lens on Cosmology). The interpretive framing used here relies explicitly on: §2.1.2 (Corrective lens versus existence explanation), §2.1.3 (The cosmological constant under RST constraints), §2.1.4 (Dark matter, inertia, and impedance), and §2.1.5 (Structure formation as irreversible redistribution).

The purpose of this appendix is diagnostic rather than reconstructive. It summarizes a set of publicly discussed observational results (primarily from JWST) that have attracted attention because they appear, at minimum, to place pressure on standard pre-JWST expectations within ΛCDM-based galaxy formation models. The aim here is not to claim falsification or resolution, but to identify regimes where assumptions of linearity, universality, and environment-independent rates are most vulnerable.

Clarifying scope and non-claims. This appendix does not claim that the observations discussed here falsify ΛCDM, nor does it propose new cosmological parameters, alternative expansion histories, or specific numerical predictions. It does not assert that Reactive Substrate Theory (RST) “explains” these datasets in a fit-level sense. Its sole purpose is to identify observational regimes where effective descriptions rely most strongly on assumptions of linearity, universality, and environment-independent rates, and to note that these regimes coincide with locations where finite, dissipative, rate-limited response—central to RST—would be expected to manifest first. The appendix is therefore diagnostic, not reconstructive.

---

1. Spectroscopically confirmed very early, luminous galaxies

JWST/NIRSpec observations have spectroscopically confirmed galaxies at redshifts z ≈ 14, corresponding to cosmic times of roughly 300 million years after the Big Bang. Because these identifications are spectroscopic rather than purely photometric, they represent one of the cleanest forms of early-universe “timeline pressure.”

Claims of record-distance galaxies continue to advance, with objects reported at z ≈ 14.4 in recent literature and associated coverage (e.g., “MoM-z14”).

ΛCDM does not forbid galaxies at such redshifts. The point of interest lies in the combination of their apparent luminosity or inferred mass and their apparent abundance at extremely high redshift.

2. Slow evolution and apparent overabundance of bright galaxies (z ≳ 9–15)

A recurring JWST-era result is that UV-bright galaxies at redshifts above z ≈ 9–10 appear more abundant, or evolve more slowly in number density, than many pre-JWST models anticipated.

Analyses from CEERS report that the space density of bright galaxies changes only modestly from z ≈ 14 to z ≈ 9, relative to earlier expectations, with increasing spectroscopic confirmation strengthening confidence in the trend.

Lensing-assisted studies from UNCOVER find evidence consistent with a bright-end excess at z > 9 and suggest that a double power-law may describe the luminosity function better than a simple Schechter form in this regime.

Multi-field efforts combining programs such as PRIMER, JADES, and NGDEEP now provide broader statistical support for mapping the UV luminosity function out to z ≈ 15.

Current literature nuance: There is an active division between interpretations that view these results as genuine tension with ΛCDM expectations and analyses that argue that consistency can be maintained once selection effects, dust, stellar population assumptions, and the mapping from UV luminosity to stellar and halo mass are treated carefully.

From the RST perspective, this category of result is relevant precisely because it probes the boundary of regime-independence: the point at which “the same parameters everywhere” becomes an approximation rather than a guarantee (see §2.1.2).

3. “Too massive too early” stellar mass claims

Some of the earliest JWST-era headlines focused on galaxies at z ≈ 7–10 with photometrically inferred stellar masses large enough to challenge standard assumptions about halo assembly efficiency. These claims were often framed as a lack of sufficiently massive halos if stellar masses were taken at face value with high efficiency.

Subsequent analyses emphasize that these inferences are highly model-dependent, with sensitivity to assumed initial mass functions, dust attenuation, star-formation history priors, nebular emission, and lensing corrections. As a result, this category remains a live but less clean diagnostic than the spectroscopically confirmed luminosity results at z ≈ 14.

4. Early black holes that appear unusually massive

JWST has strengthened evidence for very massive black holes at early epochs, in some cases appearing overmassive relative to their host galaxies. These observations suggest either rapid early accretion, heavy black hole seeds, or both.

This intersects directly with the RST interpretation of inertia and retuning cost (see §2.1.4): the early-universe regime is precisely where strong coupling and rapid reconfiguration would be expected to produce extreme compact object formation pathways without requiring new particles at the level of ontology.

A newer and still-developing category involves compact red sources (“Little Red Dots”), sometimes discussed as potential signatures of early black hole growth, though their physical interpretation remains under active investigation.

5. Early complex structures and rare interactions

JWST observations have also revealed surprisingly complex environments at early times, including rare multi-galaxy interactions and systems with strong emission-line structure well within the first billion years. These cases are often framed as surprising in terms of structure and rarity rather than as direct falsifications of ΛCDM.

Summary: what “does not neatly fit” means

The most defensible characterization of the current situation is:

• spectroscopically confirmed galaxies now extend to z ≈ 14+, and some are highly luminous,
• the bright-end abundance at z > 9–10 appears higher or evolves more slowly than many pre-JWST expectations, depending on inference assumptions,
• some early claims of extreme stellar masses are under active reassessment due to model sensitivity,
• early black hole growth remains a pressure point with increasingly strong observational support.

None of these results independently falsifies ΛCDM. Together, however, they probe regimes where assumptions of linear response, scale-free efficiency, and environment-independence are least secure.

Within RST, these are precisely the regimes where bounded response and dissipation should first appear as persistent scaling deviations rather than dramatic breakdowns—consistent with the corrective-lens framing in §2.1.2 and the irreversibility perspective emphasized in §2.1.5.