Speaker
Description
To address emerging discrepancies among key cosmological parameters, I investigate interacting dark sector models as a possible resolution to the persistent $H_0$ and $S_8$ tensions. I focus on scenarios in which dark matter interacts with quintessence or phantom dark energy.
I will present the background and perturbation equations for the coupled dark matter–dark energy model and discuss its constraints using a combination of low- and high-redshift observational datasets. Owing to uncertainties in both dark energy physics and current measurements, the inferred value and constraining power of the Hubble constant $H_0$ are found to be dataset dependent. Allowing the interaction parameter to vary freely, we find that while the interaction strength remains small, it is not disfavored by the data at late times. I will further compare results obtained assuming spatial flatness with those derived within a curved geometry framework. This analysis highlights the role of spatial curvature in addressing the ongoing cosmological tensions. I will delve deeper into how these findings within the Coupled+$Ω_K$ picture suggest that relaxing the flatness assumption leads to tighter and more robust constraints on both $H_0$ and $S_8$. I will also comment on the impact of different possible scalar-field potentials.