COSMIC MICROWAVE BACKGROUND TEMPERATURE-FLUCTUATIONS AND GRAVITATIONAL-WAVES

Temperature fluctuations in the cosmic microwave background radiation may include an important contribution from gravitational waves (tenser metric perturbations). We show here how one can calculate analyticall y these fluctuations on all angular scales. In our treatment, we inclu de the effect of the radiation-dominated period and the finite thickne ss of the last scattering surface. The adiabatic damping of gravitatio nal waves inside the horizon leads to a strong decrease in amplitude a t scales smaller than the size of the horizon at recombination.