J-PAS: forecasts on interacting vacuum energy models

TL;DR

The paper forecasts the ability of the upcoming J-PAS galaxy survey to test models where dark matter interacts with vacuum energy, providing competitive constraints compared to other major surveys.

Contribution

It introduces a framework for analyzing interacting dark sector models with future survey data, focusing on a specific model without momentum exchange and including baryons.

Findings

J-PAS can constrain interaction parameters effectively at low redshifts.

Forecasted errors on interaction parameters are comparable to current CMB data.

J-PAS's performance is competitive with DESI and Euclid surveys.

Abstract

The next generation of galaxy surveys will allow us to test some fundamental aspects of the standard cosmological model, including the assumption of a minimal coupling between the components of the dark sector. In this paper, we present the Javalambre Physics of the Accelerated Universe Astrophysical Survey (J-PAS) forecasts on a class of unified models where cold dark matter interacts with a vacuum energy, considering future observations of baryon acoustic oscillations, redshift-space distortions, and the matter power spectrum. After providing a general framework to study the background and linear perturbations, we focus on a concrete interacting model without momentum exchange by taking into account the contribution of baryons. We compare the J-PAS results with those expected for DESI and Euclid surveys and show that J-PAS is competitive to them, especially at low redshifts. Indeed, the predicted errors for the interaction parameter, which measures the departure from a $\Lambda$CDM model, can be comparable to the actual errors derived from the current data of cosmic microwave background temperature anisotropies.