Turbulence, plasma instabilities, transport and magnetogenesis in galaxy clusters

The clusters of galaxies are the largest structured objects in the Universe. Most of the luminous matter contained in clusters is in the form of ionised gas, or plasma (called the intracluster medium, or ICM). This plasma is believed to be in a turbulent state, i.e., it is moving in a disordered fashion. It is also permeated by tangled magnetic fields, which impart a certain elasticity to the plasma motions and also alter the motion of individual particles. All large scale processes in clusters - such as, for example, the propagation of waves and shocks, formation and movement of 'bubbles' blown by the active galaxies in cluster cores etc. - occur in this turbulent magnetised medium and are profoundly affected by it. This proposal is for an investigation of the fundamental physical properties of the ICM: what kind of turbulent motions and electromagnetic fluctuations exist in it? how is the energy of ICM motions dissipated into heat? how is heat trnasported across clusters? what is the origin and structure of magnetic fields in clusters? All these questions must be faced in order for us to be able to make sense of the rapidly increasing amount of observational evidence (obtained with radiotelescopes and with X-ray satellite observatories) and also to develop correct numerical models of clusters. More broadly, the problem of turbulence, which is at the centre of this research, is an exciting and formidable intellectual challenge, sometimes referred to as the last great unsolvedx problem of classical physics. Intertwined with the problem of magnetogenesis (the origin of cosmic magnetism), it continues to inspire both theoretical physicists and astronomers.