Cosmic String Wake Detection using 3D Ridgelet Transformations

Abstract

Three-dimensional ridgelet statistics are used to search for the signals of cosmic string wakes in the distribution of dark matter. We compare N-body simulations of the dark matter distribution in cosmological models with and without a cosmic string wake, assuming that the dominant sources of fluctuations are those predicted in the standard $\Lambda$CDM model. Cosmic string wakes lead to overdense regions with planar topology, and hence three-dimensional ridgelet statistics are a promising analysis tool. The string signal is easier identifiable for larger string tensions and at higher redshift. We find that a wake produced by a string of tension $G\mu = 10^{-7}$ (a value slightly lower than the best current robust upper bound) can be detected at $6 \, \sigma$ confidence level at a cosmological redshift $z = 10$.