Magnetic fields and cosmic rays in galaxy clusters and large scale structures

In galaxy clusters, non-thermal components such as magnetic field and high energy particles keep a record of the processes acting since early times till now. These components play key roles by controlling transport, processes inside the cluster atmosphere and beyond and therefore have to be understood in detail by means of numerical simulations. The complexity of the intra, cluster medium revealed by multi-frequency observations demonstrates that a variety of physical processes are in action and must be included properly to produce accurate and realistic models. Confronting the predictions of numerical simulations with Observations allows us to validate different scenarios about origin and evolution of large scale magnetic fields and to investigate their role in transport; and acceleration processes of cosmic rays.