# Constraints on Superconducting Cosmic Strings from the Global $21$-cm Signal before Reionization

## TL;DR

This paper investigates how electromagnetic emissions from superconducting cosmic strings could affect the early universe's 21cm signal, setting constraints based on recent EDGES observations to limit string properties.

## Contribution

It provides new bounds on superconducting cosmic string parameters by analyzing their impact on the global 21cm signal before reionization.

## Key findings

- Constraints on string current and tension parameters.
- Limits on electromagnetic radiation from cosmic strings.
- Compatibility with EDGES 21cm absorption feature.

## Abstract

Electromagnetic radiation from the cusp region of superconducting cosmic strings leads to a radio excess in the photon spectrum in the early universe and can produce a deep absorption feature in the global 21cm signal before the epoch of reionization. We study the constraints on the parameter space of superconducting strings which can be derived by demanding that the absorption feature is not larger in amplitude than what has recently been reported by the EDGES collaboration.