Dark Matter May Not Be a Particle: A Falsifiable Prediction for the Euclid Mission

This paper presents falsifiable, quantitative predictions for the redshift evolution of the galactic acceleration scale a₀, ahead of the Euclid DR1 data release.The radial acceleration relation (RAR), established by McGaugh et al. (2016) on 175 SPARC galaxies, encodes a universal transition between Newtonian and anomalous gravitational regimes at a characteristic scale a₀ ≈ 1.2 × 10⁻¹⁰ m/s². Standard MOND treats a₀ as a fundamental constant, identical at all cosmic epochs. We present evidence that a₀ is not constant but increases with redshift.This prediction is validated at z ~ 0.85 against 163 KROSS galaxies in the weak-gravity regime, yielding a₀(z=0.85) = 1.484 × 10⁻¹⁰ m/s², in agreement with our theoretical prediction to 0.9%, without any free parameter adjusted on galaxy data.

We apply this framework to 5,000 galaxies from the Euclid Quick Data Release 1 (Q1, March 2025) and generate explicit predictions for four redshift bins accessible to Euclid DR1 (2026): +7% at z~0.6, +17% at z~0.85 (already confirmed), +26% at z~1.5, and +35% at z~2.0.These predictions are distinct from both MOND and ΛCDM and will be directly testable when Euclid DR1 publishes resolved kinematic measurements of distant galaxies.

Data sources: KROSS public catalogue v2 (Johnson et al. 2018), Euclid Q1 catalogue (Aussel et al. 2025), Planck 2018 (Aghanim et al. 2020). SkuldRy Method.