Physics of the intracluster plasma from present and future X-ray observations

Galaxy clusters have a great promise as a tool for precision cosmology, but in order to fulfill that promise, we need a better understanding of the physical processes that govern the intracluster plasma and dark matter components. High-resolution X-ray imaging from Chandra and XMM have provided constraints on thermal conductivity, viscosity, the strength of the magnetic fields and the electron-ion equilibration timescale in the intracluster medium. Astro-H will provide the first measurements of, or stringent upper limits on, turbulence in relaxed and merging clusters. These cluster properties are extremely important for understanding the cluster energetics and interpreting the forthcoming large cosmological surveys.