COSMOLOGICAL PERTURBATIONS FROM COSMIC STRINGS

Some aspects of the theory of cosmological perturbations from cosmic s trings and other topological defects are outlined, with particular ref erence to a simple example: a spatially flat CDM-dominated universe. T he conserved energy-momentum pseudo-tensor is introduced, and the equa tion for the density perturbation derived from it. It is shown how the scaling hypothesis for defect evolution results in a Harrison-Zel'dov ich spectrum for wavelengths well inside the horizon.