Cosmic F- and D-strings

TL;DR

This paper explores the stability conditions of cosmic F- and D-strings, identifying scenarios where metastable strings, including (p,q) networks, can exist, providing insights into string physics through cosmic observations.

Contribution

It analyzes the stability and metastability of cosmic F- and D-strings, highlighting conditions for their existence and the formation of (p,q) string networks.

Findings

Metastable cosmic strings can exist in many models.

Networks of (p,q) strings are a notable possibility.

Cosmic strings offer a window into fundamental string physics.

Abstract

Macroscopic fundamental and Dirichlet strings have several potential instabilities: breakage, tachyon decays, and confinement by axion domain walls. We investigate the conditions under which metastable strings can exist, and we find that such strings are present in many models. There are various possibilities, the most notable being a network of (p,q) strings. Cosmic strings give a potentially large window into string physics.