Cosmological observations in a modified theory of gravity (MOG)
  Our modified gravity theory (MOG) is a gravitational theory without exotic
dark matter, based on an action principle. MOG has been used successfully to
model astrophysical phenomena such as galaxy rotation curves, galaxy cluster
masses, and lensing. MOG may also be able to account for cosmological
observations. We assume that the MOG point source solution can be used to
describe extended distributions of matter via an appropriately modified Poisson
equation. We use this result to model perturbation growth in MOG and find that
it agrees well with the observed matter power spectrum at present. As the
resolution of the power spectrum improves with increasing survey size, however,
significant differences emerge between the predictions of MOG and the standard
LCDM model, as in the absence of exotic dark matter, oscillations of the power
spectrum in MOG are not suppressed. We can also use MOG to model the acoustic
power spectrum of the cosmic microwave background. A suitably adapted
semi-analytical model offers a first indication that MOG may pass this test,
and correctly model the peak of the acoustic spectrum.
