# An estimate of the dark matter density from galaxy clusters and supernovae data

## TL;DR

This paper estimates the current dark matter density using a model-independent approach combining galaxy cluster gas fractions, supernovae data, and high-redshift baryon measurements, and explores potential dark matter-dark energy interactions.

## Contribution

It provides a new estimate of the dark matter density parameter without assuming a specific cosmological model and investigates the detectability of dark sector interactions.

## Key findings

- Dark matter density parameter estimated as 0.244 ± 0.013.
- Total matter density parameter estimated as 0.285 ± 0.013.
- Forecasts for future observations to detect dark sector interactions.

## Abstract

In this paper, we discuss a model-independent way to obtain the present dark matter density parameter ($\Omega_{\rm{c,0}}$) by combining gas mass fraction measurements in galaxy clusters ($f_{gas}$), type Ia supernovae (SNe Ia) observations and measurements of the cosmic baryon abundance from observations of absorption systems at high redshifts. Our estimate is $\Omega_{\rm{c,0}} = 0.244 \pm 0.013$ ($1\sigma$). By considering the latest local measurement of the Hubble constant, we obtain $\Omega_{\rm{M,0}} = 0.285 \pm 0.013$ ($1\sigma$) for the total matter density parameter. We also investigate departures of the evolution of the dark matter density with respect to the usual $a^{-3}$ scaling, as usual in interacting models of dark matter and dark energy. As the current data cannot confirm or rule out such an interaction, we perform a forecast analysis to estimate the necessary improvements in number and accuracy of upcoming $f_{gas}$ and SNe Ia observations to detect a possible non-minimal coupling in the cosmological dark sector.