The Javalambre-PAU Astrophysical Survey (J-PAS) is a very wide field Cosmological
Survey to be carried out from the Javalambre Observatory in Spain with a
purpose-built, dedicated 2.5m telescope, using a set of 54 narrow band and 5 broad
band filters over a 1.3Gpix, 5deg2 FOV camera. Starting in early 2015, J-PAS will
image 8500deg2 of Northern Sky and obtain 0.003(1 + z) precision photometric
redshifts for 90M galaxies, > 50 times more than the largest current spectroscopic
survey, sampling an effective volume of ∼ 16 Gpc3. Thanks to its innovative design,
J-PAS will be the first experiment to reach a factor of 100 improvement over current
constraints in the Dark Energy FoM, by 2020, before other Stage IV projects like
Euclid and LSST start their operations. The instrumental development of J-PAS
involves a small fraction of the cost and complexity of a high multiplexing
spectrograph, yet it will produce data which enable a much wider range of
Astrophysical applications: J-PAS effectively uses a 5deg2 IFU which will produce
a 3D image of the Extragalactic Northern sky. J-PAS will have a lasting legacy value,
serving as a fundamental dataset for future projects.