We assess the contribution to the observed large scale anisotropy of the cosmic microwave background radiation, arising from both gravity waves as well as adiabatic density perturbations, generated by a common inflationary mechanism in the early Universe. We find that for inflationary models predicting power law primordial spectra |δk|2∝kn, the relative contribution to the quadrupole anisotropy from gravity waves and scalar density perturbations, depends crucially upon n. For n<0.84, gravity waves perturb the CMBR by a larger amount than density perturbations, whereas for n>0.84 the reverse is true. Normalizing the amplitude of the density perturbation spectrum at large scales, using the observed value of the COBE quadrupole, we determine (δM/M)16-the rms density contrast on scales [Formula: see text] Mpc, for cosmological models with cold dark matter. We find that for n<0.75, a large amount of biasing is required in order to reconcile theory with observations. We also determine the value of the inflationary Hubble parameter and the COBE-normalized amplitude and spectrum of gravity waves from inflation.
Density perturbations in generalized Einstein scenarios and constraints on nonminimal couplings from the cosmic microwave background