Limits on Black Hole Formation from Cosmic String Loops

TL;DR

This paper reviews constraints on black hole formation from cosmic string loops, analyzing observational limits like Hawking radiation and cosmic rays, and finds these constraints closely match those from cosmic microwave background data.

Contribution

It provides a comprehensive reanalysis of observational constraints on black holes formed from cosmic string loops, connecting different astrophysical limits.

Findings

Hawking radiation limits restrict black hole formation from cosmic strings.

Cosmic ray flux measurements provide significant constraints.

Constraints align closely with cosmic microwave background normalization.

Abstract

In theories with cosmic strings, a small fraction of string loops may collapse to form black holes. In this Letter, various constraints on such models involving black holes are considered. Hawking radiation from black holes, gamma and cosmic ray flux limits and constraints from the possible formation of stable black hole remnants are reanalyzed. The constraints which emerge from these considerations are remarkably close to those derived from the normalization of the cosmic string model to the cosmic microwave background anisotropies.