Disruption of Cosmic String Wakes by Gaussian Fluctuations

Abstract

We study the stability of cosmic string wakes against the disruption by the dominant Gaussian fluctuations which are present in cosmological models. We find that for a string tension given by $G\mu =10^{-7}$ wakes remain locally stable until a redshift of $z=6$, and for a value of $G\mu =10^{-14}$ they are stable beyond a redshift of $z=20$. We study a global stability criterion which shows that wakes created by strings at times after $t_{eq}$ are identifiable up to the present time, independent of the value of $G\mu$. Taking into account our criteria it is possible to develop strategies to search for the distinctive position space signals in cosmological maps which are induced by wakes.

Comments: 10 pages, 3 figures. We have added a paragraph to the conclusion discussing the experimental prospects from the Square Kilometre Array of observing a $G\mu =10^{-9}$ wake. Some typos were also corrected. The text now agrees with the published version