Analytical Approach to Subhaloes Population in Dark Matter Haloes

Understand

In the standard model of cosmic structure formation, dark matter haloes form by gravitational instability.

• The process is hierarchical: smaller systems collapse earlier, and later merge to form larger haloes.
• The galaxy clusters, hosted by the largest dark matter haloes, are at the top of this hierarchy representing the largest as well as the last structures formed in the universe, while the smaller and first haloes are those Earth-sized dark subhaloes which have been both predicted by theoretical considerations and found in numerical simulations, though it does not exist any observational hints of their existence.
• The probability that a halo of mass $m$ at redshift $z$ will be part of a larger halo of mass $M$ at the present time can be described in the frame of the extended Press & Schecter theory making use of the progenitor (conditional) mass function.