Local Axion Cosmic Strings from Superstrings

TL;DR

This paper explores axionic cosmic strings within a superstring-inspired model, revealing finite energy solutions, analyzing fermion zero modes, and discussing cosmological implications and bounds.

Contribution

It introduces local axion string solutions with finite energy in a superstring context and examines fermion zero modes and their cosmological effects.

Findings

Finite energy axion string solutions found

Fermion zero modes analyzed and linked to supersymmetry

Cosmological bounds on the model are weakened by string properties

Abstract

Axionic cosmic string solutions are investigated in a superstring motivated model with a pseudo-anomalous U(1) gauge symmetry. The inclusion of a gauge field and spatially varying dilaton allow local defect solutions with finite energy per unit length to be found. Fermion zero modes (whose presence is implied by supersymmetry) are also analysed. The corresponding fermion currents suggest strong cosmological bounds on the model. It is shown that the unusual form of the axion strings weakens these bounds. Other cosmological constraints on the underlying theory are also discussed.