Constraining interacting dark energy models with the halo concentration-mass relation

Understand

The interacting dark energy (IDE) model is a promising alternative cosmological model which has the potential to solve the fine-tuning and coincidence problems by considering the interaction between dark matter and dark energy.

• Previous studies have shown that the energy exchange between the dark sectors in this model can significantly affect the dark matter halo properties.
• In this study, utilising a large set of cosmological $N$-body simulations, we analyse the redshift evolution of the halo concentration-mass ($c$-$M$) relation in the IDE model, and show that the $c$-$M$ relation is a sensitive proxy of the interaction strength parameter $\xi_2$, especially at lower redshifts.
• Furthermore, we construct parametrized formulae to quantify the dependence of the $c$-$M$ relation on $\xi_2$ at redshifts ranging from $z=0$ to $0.6$.