A fake Interacting Dark Energy detection?

TL;DR

This paper investigates whether current and future CMB data can reliably detect or falsely suggest interactions between Dark Matter and Dark Energy, highlighting the importance of simulations in cosmological analyses.

Contribution

It demonstrates that current Planck data may lead to false detections of Dark Sector interactions, and emphasizes the need for future polarization experiments to obtain trustworthy constraints.

Findings

Current Planck data can produce fake signals of Dark Sector interaction.

Future polarization experiments like PICO or PRISM can reliably constrain interactions.

Simulations are crucial for validating cosmological parameter estimates.

Abstract

Models involving an interaction between the Dark Matter and the Dark Energy sectors have been proposed to alleviate the long standing Hubble constant tension. In this paper we analyze whether the constraints and potential hints obtained for these interacting models remain unchanged when using simulated Planck data. Interestingly, our simulations indicate that a dangerous fake detection for a non-zero interaction among the Dark Matter and the Dark Energy fluids could arise when dealing with current CMB Planck measurements alone. The very same hypothesis is tested against future CMB observations, finding that only cosmic variance limited polarization experiments, such as PICO or PRISM, could be able to break the existing parameter degeneracies and provide reliable cosmological constraints. This paper underlines the extreme importance of confronting the results arising from data analyses with those obtained with simulations when extracting cosmological limits within exotic cosmological scenarios.