Angular Correlation Functions for Models with Logarithmic Oscillations
  There exist several theoretical motivations for primordial correlation
functions (such as the power spectrum) to contain oscillations as a logarithmic
function of comoving momentum k. While these features are commonly searched for
in k-space, an alternative is to use angular space; that is, search for
correlations between the directional vectors of observation. We develop tools
to efficiently compute the angular correlations based on a stationary phase
approximation and examine several example oscillations in the primordial power
spectrum, bispectrum, and trispectrum. We find that logarithmically-periodic
oscillations are essentially featureless and therefore difficult to detect
using the standard correlator, though others might be feasible.
