Cosmic strings with positive $\Lambda$

TL;DR

This paper explores the properties and effects of cosmic Nielsen-Olesen strings in space-times with a positive cosmological constant, analyzing their geometry, geodesics, and interactions with horizons.

Contribution

It provides new insights into how a positive cosmological constant influences cosmic string geometry, geodesic motion, and horizon piercing in Schwarzschild-de Sitter space.

Findings

Positive $\Lambda$ affects the angle deficit of cosmic strings.

Thin strings can pierce horizons in Schwarzschild-de Sitter space.

A new metric describes the exterior of a self-gravitating string in this context.

Abstract

We discuss cosmic Nielsen-Olesen strings in space-times endowed with a positive cosmological constant. For the cylindrically symmetric, static free cosmic string, we discuss the contribution of the cosmological constant to the angle deficit, and to the motion of the null/timelike geodesics. For a non-gravitating cosmic string in a Schwarzschild-de Sitter space-time, we discuss how a thin string can pierce the two horizons. We also present a metric which describes the exterior of a self gravitating thin string present in the Schwarzschild-de Sitter space-time.