Quantum Fixed Point and Cosmic Invariance: The Non-evolution of the Baryonic Tully-Fisher Relation up to z∼ 7.3

The Baryonic Tully-Fisher Relation (BTFR)—connecting galaxy rotation velocity to baryonicmass—is a fundamental scaling relation in extragalactic astronomy. Standard ΛCDM predictionssuggest that the BTFR should evolve with cosmic time due to hierarchical mass assembly and thegrowth of dark matter halos. However, recent high-redshift observations of dynamically cold diskgalaxies provide an unprecedented opportunity to test these predictions. We present a comprehensiveanalysis of three high-redshift disk galaxies spanning z = 2.1 to z = 7.3, combining data from Liu etal. (2024), Pensabene et al. (2025), and Rowland et al. (2024), all exhibiting remarkably consistentkinematic coldness (Vrot/σ∼ 9− 11). We find that all three systems lie on or very near the localSPARC BTFR relation, indicating no significant evolution of the BTFR over the past 5 billion years ofcosmic history. This observational result stands in striking tension with ΛCDM predictions of gradualBTFR evolution, with observed velocity dispersions and rotation velocities differing from theoreticalexpectations by factors of 8-10. By contrast, these observations are consistent with the predictionsof q-deformed Effective Field Theory (q-EFT), which posits that a quantum topological fixed pointis conserved during galaxy assembly, maintaining a constant rotation-support ratio regardless of red-shift. We discuss the implications for early galaxy assembly, the role of cold-mode accretion, and thenecessity of rethinking dark matter’s role in high-redshift disk galaxy dynamics.