Large-scale anisotropy of the microwave background and the amplitude of energy density fluctuations in the early universe

The spectrum of energy density fluctuations predicted by the inflationary cosmology is used to compute multipole moments of the microwave background temperature and the probability distributions for these moments. Comparison with the observed dipole moment gives a 90% confidence level upper bound of 3.4×10⁻⁶ on the amplitude of these fluctuations when they cross the horizon.