Statistical Mechanics of the Cosmological Many-body Problem and its
  Relation to Galaxy Clustering
  The cosmological many-body problem is effectively an infinite system of
gravitationally interacting masses in an expanding universe. Despite the
interactions' long-range nature, an analytical theory of statistical mechanics
describes the spatial and velocity distribution functions which arise in the
quasi-equilibrium conditions that apply to many cosmologies. Consequences of
this theory agree well with the observed distribution of galaxies. Further
consequences such as thermodynamics provide insights into the physical
properties of this system, including its robustness to mergers, and its
transition from a grand canonical ensemble to a collection of microcanonical
ensembles with negative specific heat.
