Motivation
Magnetic fields are present in almost every place in the Universe.
Most of the luminous matter is tightly coupled to magnetic fields.
Large-scale fields intersperse the gas in the Milky Way, in galaxies
and in galaxy clusters. They contribute to the nonlinear interplay of
turbulent motions in the interstellar and intracluster medium. The
magnetic energy content affects the evolution of galaxies and
galaxy clusters, contributes significantly to the total pressure of
interstellar gas, is essential for the onset of star formation, and
controls the density and distribution of cosmic rays in the
interstellar medium (ISM). In spite of their importance, the
evolution, structure and origin of magnetic fields are still open
problems in fundamental physics and astrophysics.