Cosmic microwave background anisotropies from scaling seeds: Generic properties of the correlation functions

In this work we present a partially new method to analyze fluctuations which are induced by causal scaling seeds. We show that the power spectra due to these kinds of seed perturbations are determined by five analytic functions, which we determine numerically for a special example. We put forward the view that, even if recent work disfavors the models with cosmic strings and global $O(4)$ texture, causal scaling seed perturbations merit a more thorough and general analysis, which we initiate in this paper.