Dark matter from cosmic defects on galactic scales?

TL;DR

This paper explores whether extended cosmic defects could serve as dark matter on galactic scales, but finds observational constraints largely exclude this possibility, especially for standard defect models.

Contribution

It evaluates the potential of various cosmic defect models to explain galactic dark matter and demonstrates observational data limits their viability.

Findings

Standard defects are unsuitable as dark matter candidates.

Transonic wiggly strings could potentially explain dark matter.

Observational data severely restricts defect-based dark matter scenarios.

Abstract

We discuss the possible dynamical role of extended cosmic defects on galactic scales, specifically focusing on the possibility that they may provide the dark matter suggested by the classical problem of galactic rotation curves. We emphasize that the more standard defects (such as Goto-Nambu strings) are unsuitable for this task, but show that more general models (such as transonic wiggly strings) could in principle have a better chance. In any case, we show that observational data severely restricts any such scenarios.