Black Hole Formation from Loops of Cosmic Strings

Abstract

We study linearized perturbations on cosmic strings, taking into account the frictional force due to the interaction of strings with matter. We then analyze the formation of black holes through collapsing loops of strings. Such black holes can evaporate via Hawking radiation, producing γ-bursts. We conclude that currently evaporating black holes cannot, through γ-ray background observations, impose limits on the density of cosmologically interesting cosmic strings.