Abstract
The J-PAS and the WEAVE surveys have finally started observations in 2023. J-PAS will detect $\sim10^4$ galaxies/deg$^2$ to produce a high-density 3D map of the Universe up to $z\sim 1$, but one of its key science drivers is cosmology with quasars. By combining J-PAS with the WEAVE-QSO survey we can unlock the full potential of high-redshift quasars, using those objects not only as tracer…