ΛCDM predicts:
WIMP-nucleon cross-section above 10−48 cm2; detectable with current-generation experiments.
Khronon predicts:
No dark matter particles exist. All searches return null.
Observation:
40+ years of null results across all channels. LZ (2024–2025) excludes the remaining natural WIMP parameter space with zero signal.
Verdict: Modified Gravity
LZ Collaboration (2024, 2025); PandaX-4T (2024); XENON-nT (2024)
ΛCDM predicts:
No universal relation between baryonic and total acceleration. Scatter depends on halo assembly history.
Khronon predicts:
Universal 1-parameter relation gobs = gbar / (1 − exp(−√(a0/gbar))) with a0 = cH0/2π.
Observation:
Tight universal relation with 0.13 dex intrinsic scatter across 175 SPARC galaxies spanning 4 decades in mass. Residuals uncorrelated with galaxy properties.
Verdict: Modified Gravity
McGaugh, Lelli & Schombert (2016); Lelli et al. (2017)
ΛCDM predicts:
Slope 3.0–3.5 with significant scatter from variable halo concentration and feedback.
Khronon predicts:
Exact slope = 4.0, zero intrinsic scatter (Mbar = Vf4 / (G a0)). Predicted by Milgrom (1983), a priori.
Observation:
Slope = 3.98 ± 0.07, intrinsic scatter consistent with zero (<0.1 dex), holding over 5 decades in baryonic mass.
Verdict: Modified Gravity
McGaugh (2012); Lelli, McGaugh & Schombert (2016)
ΛCDM predicts:
NFW cusps (ρ ~ r−1) in all halos. Baryonic feedback may flatten to cores in bright dwarfs only.
Khronon predicts:
No dark halo → no cusp. Core-like profiles emerge naturally from the baryonic mass distribution.
Observation:
Cores observed ubiquitously, including in ultra-faint dwarfs where baryonic feedback is negligible. Feedback-based solutions fail for M* < 106 Msun.
Verdict: Modified Gravity
de Blok (2010); Read et al. (2019); Hayashi et al. (2020)
ΛCDM predicts:
Isotropic satellite distribution. Thin co-rotating planes have <0.5% probability in cosmological simulations.
Khronon predicts:
Satellites are tidal debris from past interactions, naturally forming planar co-rotating structures.
Observation:
Thin co-rotating satellite planes found in the Milky Way (VPOS), M31 (GPoA), and Centaurus A. Three independent systems all show the same pattern.
Verdict: Modified Gravity
Pawlowski (2018); Müller et al. (2018, 2021)
ΛCDM predicts:
No mechanism for external gravitational field to affect internal dynamics. Dark matter halos shield internal dynamics.
Khronon predicts:
Unique MOND prediction: external field breaks internal boost invariance. Galaxies in dense environments should show weaker anomalous acceleration.
Observation:
Detected at 8–11σ significance using 153 SPARC galaxies binned by external field strength. Effect matches the predicted sign and magnitude.
Verdict: Modified Gravity
Chae et al. (2020, 2021); Pittordis & Sutherland (2023)
ΛCDM predicts:
Massive high-redshift mergers of this magnitude are extremely rare. Expected relative velocity < 2000 km/s at z = 0.87.
Khronon predicts:
Enhanced gravitational dynamics at large scales allow faster infall velocities and earlier structure formation.
Observation:
El Gordo (ACT-CL J0102-4915): M ≈ 3 × 1015 Msun at z = 0.87 with infall velocity ~2500 km/s. 6.2σ tension with ΛCDM expectations.
Verdict: Modified Gravity
Asencio et al. (2023); Molnar & Broadhurst (2015)
ΛCDM predicts:
Hundreds to thousands of subhalos per Milky Way-mass galaxy. Baryonic physics suppresses star formation in most.
Khronon predicts:
Fewer satellites overall; those observed are tidal dwarf galaxies.
Observation:
DES, DESI, and deep surveys now finding ultra-faint dwarfs at the rate ΛCDM predicts once completeness corrections are applied. Gap is closing.
Verdict: ΛCDM
Drlica-Wagner et al. (2020); Kim et al. (2024)
ΛCDM predicts:
Lensing mass peak offset from X-ray gas, co-located with galaxies. Collisionless dark matter passes through while gas is shocked.
Khronon predicts:
Modified gravity predicts lensing follows mass distribution. The gas-lensing offset is difficult to reproduce without a collisionless component.
Observation:
Lensing peaks clearly offset from gas, co-located with galaxy distribution. Reproduced in multiple merging clusters (Bullet, Musket Ball, Baby Bullet).
Verdict: ΛCDM
Clowe et al. (2006); Markevitch et al. (2004)
ΛCDM predicts:
NFW halo profiles fit cluster-scale masses (1014–1015 Msun) with well-constrained c-M relation.
Khronon predicts:
Modified gravity should explain cluster masses from baryons alone. MOND-class theories persistently under-predict by a factor of ~2.
Observation:
MOND leaves a residual factor-of-2 mass discrepancy in clusters. ΛCDM fits cluster masses well with standard NFW profiles and known baryonic fractions.
Verdict: ΛCDM
Sanders (2003); Pointecouteau & Silk (2005); Angus et al. (2008)
ΛCDM predicts:
Features in rotation curves correlate with baryonic features via feedback-mediated coupling. Scatter expected from halo diversity.
Khronon predicts:
Strict 1:1 correspondence between baryonic surface density features and rotation curve features. No exceptions.
Observation:
Correlation exists but data quality is ambiguous. Recent analysis (Ko+ 2025) finds cases both supporting and challenging the strict rule.
Verdict: Draw
Sancisi (2004); Ko et al. (2025)
ΛCDM predicts:
Massive subhalos should host bright satellites. Baryonic feedback + reionization may suppress star formation in most.
Khronon predicts:
No massive dark subhalos exist. Observed satellite kinematics reflect baryonic mass directly.
Observation:
Both frameworks claim partial resolution. ΛCDM via baryonic physics + stochasticity; MG via lack of massive subhalos. Neither fully satisfactory.
Verdict: Draw
Boylan-Kolchin et al. (2011); Papastergis et al. (2015)
ΛCDM predicts:
Massive galaxies at z > 10 should be extremely rare. Hierarchical assembly takes time.
Khronon predicts:
Enhanced early structure formation via modified gravitational instability. Massive galaxies at high z less surprising.
Observation:
JWST finds surprisingly massive galaxies at z = 10–14. Slight MG edge, but ΛCDM is adjusting models (enhanced star formation efficiency, reduced feedback). Jury still out.
Verdict: Draw (slight MG edge)
Labbé et al. (2023); Boylan-Kolchin (2023); Haslbauer et al. (2024)
ΛCDM predicts:
Lensing mass traces NFW profile. Galaxy-galaxy lensing and cluster lensing well-fit by standard halo models.
Khronon predicts:
Galaxy-scale lensing follows from modified potential (exponential metric). Cluster-scale lensing may show residual discrepancy.
Observation:
Galaxy-scale: competitive, with Fagin (2024) SLACS data slightly favoring MG-like profiles. Cluster-scale: ΛCDM remains better. Overall: draw.
Verdict: Draw (galaxy ~ MG, cluster ~ ΛCDM)
Fagin et al. (2024); Brouwer et al. (2017, 2021)