# Signature of the interaction between dark sectors in the reionization process

## TL;DR

This paper investigates how interactions between dark matter and dark energy influence the reionization history and 21 cm signals, revealing potential deviations from the standard cosmological model.

## Contribution

It introduces a semi-analytical model to study the impact of dark sector interactions on reionization and compares the resulting 21 cm signals with the standard ΛCDM predictions.

## Key findings

- Dark sector interactions can significantly alter reionization history
- Interactions affect the amplitude and timing of 21 cm signals
- Potential observational signatures distinguishable from ΛCDM

## Abstract

We consider the reionization process in a cosmological model in which dark matter interacts with dark energy. Using a semi-analytical reionization model, we compute the evolution of the ionized fraction in terms of its spatial average and linear perturbations. We show that certain types of interactions between dark matter and dark energy can significantly affect the reionization history. We calculate the 21 cm signals in the interaction models, and compare the results with the predictions of the ${\rm \Lambda CDM}$ model.