Clusters of galaxies are both unique astrophysical laboratories and powerful cosmological probes. They are thus a veritable crossroads of cosmology and astrophysics.   A series of ongoing and planned multi-wavelength surveys promise an unprecedented wealth of data on clusters.  Progress in our understanding of these systems therefore require a holistic approach which tightly integrates comparisons of observations and theoretical models of both detailed physics of clusters and their statistical properties as a population.

This program aims to bring together observers and theorists studying the astrophysics of clusters and their cosmological applications in the unique setting of KITP. The aim is to foster cross-fertilization between these two communities via focused talks, discussion sessions, and collaborative work.

The program will focus on the following broad themes and questions:

• Physics of the intracluster medium (e.g., turbulence, conduction, thermal and non-thermal plasma processes)
• Models of cluster formation and evolution
• Galaxies in galaxy clusters and interplay between galaxies and ICM; AGN feedback
• Geometrical and structure growth cosmological constraints using clusters
• Cluster scaling relations and mass indicators
• Novel ways of using clusters as cosmological probes; synergy between clusters and other cosmological probes and next generation cluster observations

A conference (This conference is now full) will be held during the week of March 14-18, 2011, which will review new scientific results ranging from meter-wave radio to gamma rays, as well as state of the art in theoretical modeling of clusters.