Cosmic (super)string constraints from 21 cm radiation

TL;DR

This paper explores how future 21 cm radiation observations can significantly constrain cosmic string models, potentially probing string tensions much lower than current experimental limits, thus testing early universe theories.

Contribution

It demonstrates that upcoming large-scale 21 cm surveys could detect or constrain cosmic strings with very low tension, expanding the observational window into early universe physics.

Findings

Future 21 cm experiments can constrain cosmic string tension Gu > 10^(-10) to 10^(-12)

Current experiments are insufficient for meaningful constraints

Proposed methods can test brane inflation models with high sensitivity

Abstract

We calculate the contribution of cosmic strings arising from a phase transition in the early universe, or cosmic superstrings arising from brane inflation, to the cosmic 21 cm power spectrum at redshifts z > 30. Future experiments can exploit this effect to constrain the cosmic string tension Gu and probe virtually the entire brane inflation model space allowed by current observations. Although current experiments with a collecting area of ~ 1 km^2 will not provide any useful constraints, future experiments with a collecting area of 10^4-10^6 km^2 covering the cleanest 10% of the sky can in principle constrain cosmic strings with tension Gu > 10^(-10) to 10^(-12) (superstring/phase transition mass scale >10^13 GeV).