Cosmic Superstrings Stabilized by Fermions

TL;DR

This paper demonstrates that fermionic zero modes on superstring worldsheets can stabilize string loops, potentially leading to cosmologically significant stable string configurations within perturbative string theory.

Contribution

It introduces a new class of massive perturbative superstring states stabilized by fermionic zero modes, impacting cosmological models and string stability analysis.

Findings

Existence of stable superstring loops due to fermionic zero modes.

Fermionic degrees of freedom act like a persistent current, stabilizing the string.

Potential implications for cosmology and long-lived string states.

Abstract

We show that there exist massive perturbative states of the ten dimensional Green-Schwarz closed superstring that are stabilized against collapse due to presence of fermionic zero modes on its worldsheet. The excited fermionic degrees of freedom backreact on the spacetime motion of the string in the same way as a neutral persistent current would, rendering these string loops stable. We point out that the existence of these states could have important consequences as stable loops of cosmological size as well as long lived states within perturbative string theory.