There is no dark matter; gravity is modified (MOND)
The observed anomalies reflect a breakdown of Newtonian/Einsteinian gravity at low accelerations rather than unseen mass.
2 open contradictions
- Evidential: These hypotheses draw opposite conclusions from the same evidence. Conflicts with Dark matter is a new fundamental particle.
- Evidential: These hypotheses draw opposite conclusions from the same evidence. Conflicts with Dark energy is a cosmological constant.
Evidence balance
Supporting
2- MOND fits galactic dynamics with one parameterw60
Mordehai Milgrom · 1983 · Peer-reviewed
The radial-acceleration relation is MOND's strongest evidence.
- Flat galaxy rotation curvesw50
Vera C. Rubin & W. Kent Ford · 1970 · Observation
Flat rotation curves can be read as modified dynamics.
Opposing
2- Bullet Cluster: mass and gas are spatially separatedw80
Clowe et al. · 2006 · Peer-reviewed
The Bullet Cluster is the strongest evidence against pure modified gravity.
- Cosmic microwave background power spectrumw75
Planck Collaboration · 2020 · Peer-reviewed
The CMB peaks are very hard for MOND without adding dark matter.
Assumptions
A relativistic completion of MOND can fit cosmology
unjustified
The Bullet Cluster can be explained without dark matter
unjustified — This is the strongest objection.
Open questions within this hypothesis
- How to fit the CMB power spectrum?
- What is the covariant theory?
Falsification criteria
The clean separation of mass and gas in colliding clusters, and the CMB acoustic peaks, are strong evidence against it; a confirmed dark-matter particle would falsify it.