Quiet sun magnetism: a new perspective from GRIS / GREGOR

The amount of magnetic flux, the field strength and its angular distribution in internetwork regions in the solar photosphere is a controversial topic in the literature. The reason for the controversy lies in the difficulty of measuring these quantities: Zeeman effect based measurements suffer from signal cancellation of oppositely directed, unresolved fields and the different sensitivity to longitudinal and transversal fields. Hanle effect based measurements require highly accurate spectropolarimeters and a good modelling of the depolarization mechanisms. In this review I will present the status of this controversial discussion as well as new results originating from high-resolution spectropolarimetric measurements in the magnetic highly sensitive Fe I 1.56 micron lines obtained with the infrared spectrograph GRIS at the GREGOR telescope.