# J-PAS: forecasts on interacting dark energy from baryon acoustic oscillations and redshift-space distortions

## TL;DR

This paper forecasts the ability of the J-PAS survey to constrain parameters of interacting dark energy models using baryon acoustic oscillations and redshift-space distortions, comparing its performance with DESI and Euclid.

## Contribution

It provides the first detailed forecast of J-PAS's constraints on interacting dark energy parameters using Fisher matrix analysis.

## Key findings

- J-PAS can constrain the interaction parameter with an uncertainty of about 0.02.
- Constraints on dark energy's equation of state are slightly better with J-PAS than other surveys.
- Euclid outperforms J-PAS and DESI, but J-PAS remains competitive.

## Abstract

We estimate the constraining power of J-PAS for parameters of an interacting dark energy cosmology. The survey is expected to map several millions of luminous red galaxies, emission line galaxies and quasars in an area of thousands of square degrees in the northern sky with precise photometric redshift measurements. Forecasts for the DESI and Euclid surveys are also evaluated and compared to J-PAS. With the Fisher matrix approach, we find that J-PAS can place constraints on the interaction parameter comparable to those from DESI, with an absolute uncertainty of about $0.02$, when the interaction term is proportional to the dark matter energy density, and almost as good, of about $0.01$, when the interaction is proportional to the dark energy density. For the equation of state of dark energy, the constraints from J-PAS are slightly better in the two cases (uncertainties $0.04$ - $0.05$ against $0.05$ - $0.07$ around the fiducial value $-1$). Both surveys stay behind Euclid but follow it closely, imposing comparable constraints in all specific cases considered.