Claim: Dark Matter Must Exist — Nothing Else Can Explain Flat Rotation Curves

The dark matter hypothesis is built on two separate foundations. The first is observational: something is causing galaxies to rotate in ways that visible mass alone cannot explain, and something is holding galaxy clusters together that visible mass alone cannot account for. The second is experimental: if dark matter is a particle, it should be detectable, and we have been trying to detect it for decades.

The observational foundation is real. Flat rotation curves and the virial mass discrepancy in galaxy clusters are genuine measurements that require explanation. But explaining them does not require dark matter specifically. It requires something. The question is whether that something is an undetected exotic particle, or whether the observations have an alternative physical explanation.

The experimental foundation has collapsed. Every major direct detection experiment has returned null results.

The Detection Record

The experimental programme to detect dark matter directly began in the 1980s and has intensified steadily. The strategy has been to look for WIMPs — Weakly Interacting Massive Particles — interacting with atomic nuclei in ultra-sensitive detectors. The record is unambiguous.

CDMS (Cryogenic Dark Matter Search): Operating since the 1990s across multiple generations of detectors in the Soudan Underground Laboratory. No confirmed detection. Each generation placed progressively more stringent upper limits on the WIMP interaction cross-section, systematically eliminating the most accessible parameter space.

LUX (Large Underground Xenon): At the time of its operation one of the world's most sensitive dark matter detectors. Final results published 2017. No signal above background. LUX's null result eliminated WIMP models that had been considered well-motivated by supersymmetry.

XENON1T and XENONnT: Located at Gran Sasso National Laboratory, Italy. The world's most sensitive detector of its generation. No dark matter signal. XENONnT extended sensitivity by another order of magnitude. Still no signal.

PandaX: China's major liquid xenon dark matter experiment. Multiple generations of increasingly sensitive detectors. No detection.

LHC: The Large Hadron Collider at CERN has searched for dark matter production through missing energy signatures. No evidence for WIMP production at any accessible energy scale. The supersymmetric particles predicted to be dark matter candidates — neutralinos, for example — have not appeared.

The Response to Null Results

The response to each null result has followed a consistent pattern: extend the search to lower cross-sections, higher masses, or different particle candidates. The axion — a different dark matter candidate — has become increasingly prominent as WIMP searches have come up empty. ALP searches, sterile neutrino searches, and primordial black hole proposals have all expanded the theoretical space.

This pattern is not inherently unscientific. Absence of detection at one parameter range does not rule out detection at another. But the cumulative effect of decades of null results across every accessible parameter space is epistemologically significant. At what threshold of non-detection does continued commitment to a hypothesis require justification beyond the persistence of the initial observations?

The BFUT Alternative for Flat Rotation Curves

The Big Flare-Up Theory explains flat galactic rotation curves through the vortex structure of galactic cores. Every galaxy contains a central gravitational vortex — not a singularity. Matter orbiting within the vortex structure experiences centripetal force from both the enclosed mass and the angular momentum distribution of the vortex itself. The Kerr metric, which describes rotating massive objects in general relativity, predicts exactly this angular momentum distribution.

A proof-of-concept simulation of 200 bodies with net angular momentum produces flat rotation curves with outer-to-inner velocity ratio of 0.71, rising to 0.78-0.85 at larger N. Angular momentum is conserved throughout. No hidden mass is required. The simulation is available at vijayshankarsharma.com/theory.

For galaxy clusters, the BFUT explanation points to the Wagner, Benisty and Karachentsev (2026) finding that the dynamics of the M81 and Centaurus A groups are fully accounted for by the visible baryonic mass of their brightest member galaxies, without requiring a group-scale dark matter halo. The observational motivation for dark matter at group scales is weaker than commonly presented.