McCulloch, M.E. Astrophys Space Sci (2012) 342: 575. doi:10.1007/s10509-012-1197-0
Galaxies and galaxy clusters have rotational velocities (v) apparently too fast to allow them to be gravitationally bound by their visible matter (M). This has been attributed to the presence of invisible (dark) matter, but so far this has not been directly detected. Here, it is shown that a new model that modifies inertial mass by assuming it is caused by Unruh radiation, which is subject to a Hubble-scale (Θ) Casimir effect predicts the rotational velocity to be: v4=2GMc2/Θ (the Tully-Fisher relation) where G is the gravitational constant, M is the baryonic mass and c is the speed of light. The model predicts the outer rotational velocity of dwarf and disk galaxies, and galaxy clusters, within error bars, without dark matter or adjustable parameters, and makes a prediction that local accelerations should remain above 2c2/Θ at a galaxy’s edge.