# Light majoron cold dark matter from topological defects and the formation of boson stars

## TL;DR

This paper explores how light majorons, produced non-thermally from topological defects, could serve as dark matter and form boson stars, with implications for future detection experiments.

## Contribution

It demonstrates that light majorons can be efficiently produced non-thermally from topological defects and can account for dark matter within a unification-scale framework.

## Key findings

- Majorons can be a viable dark matter candidate for masses much less than 100 eV.
- Non-thermal production from topological defects can generate sufficient majoron abundance.
- Formation of boson stars from majoron dark matter is possible.

## Abstract

We show that for a relatively light majoron ($\ll 100 $ eV) non-thermal production from topological defects is an efficient production mechanism. Taking the type I seesaw as benchmark scheme, we estimate the primordial majoron abundance and determine the required parameter choices where it can account for the observed cosmological dark matter. The latter is consistent with the scale of unification. Possible direct detection of light majorons with future experiments such as PTOLEMY and the formation of boson stars from the majoron dark matter are also discussed.