Black Strings in Our World

TL;DR

This paper explores the formation of black strings in a brane world scenario, showing that merging cosmic strings could produce black strings without fine-tuning parameters, highlighting higher-dimensional effects in gravity.

Contribution

It demonstrates a new mechanism for black string formation via cosmic string mergers in a brane world model with minimal scalar fields.

Findings

Black strings can form from cosmic string mergers.

No fine-tuning of parameters is required.

Higher-dimensional effects influence classical gravity at short distances.

Abstract

The brane world scenario is a new approach to resolve the problem on how to compactify the higher dimensional spacetime to our 4-dimensional world. One of the remarkable features of this scenario is the higher dimensional effects in classical gravitational interactions at short distances. Due to this feature, there are black string solutions in our 4-dimensional world. In this paper, assuming the simplest model of complex minimally coupled scalar field with the local U(1) symmetry, we show a possibility of black-string formation by merging processes of type I long cosmic strings in our 4-dimensional world. No fine tuning for the parameters in the model might be necessary.