Modelling formation of galaxy clusters: current status and challenges

Andrey Kravtsov

May 30, 2012

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Abstract: I will briefly review our current theoretical understanding of galaxy cluster formation from peaks in the primordial density field, highlighting both well-established aspects of our understanding of this process and some of the remaining puzzles. The former provide the basis for using clusters to derive cosmological constraints, while the latter define systematic errors of such constraints. I will show that the current status of our understanding of cluster formation is schizophrenic: a number of key observed properties of clusters can be explained naturally in ab initio models of cluster formation, while some other basic properties, such as total baryon content and entropy distribution, are not predicted correctly. In addition, I will argue that we do not yet have a complete baseline model for the evolution of cluster mass-observable relations and will discuss some steps towards development of such a model.