Cosmic jets: their dynamics and the role of the magnetic field

Jets are observed to be ejected from a wide variety of cosmic objects, ranging from active galactic nuclei to stellar mass black holes and protostars. Despite their different scales and bulk velocities, they have similar morphology and most likely share a common driving mechanism. In this talk, I will discuss our current understanding on the energy extraction, bulk acceleration, stability of jets, and their connection to the magnetic fields.