Zeldovich pancakes at redshift zero: the equilibration state and phase
  space properties
  One of the components of the cosmic web are sheets, which are commonly
referred to as Zeldovich pancakes. These are structures which have only
collapsed along one dimension, as opposed to filaments or galaxies and cluster,
which have collapsed along two or three dimensions. These pancakes have
recently received renewed interest, since they have been shown to be useful
tools for an independent method to determine galaxy cluster masses. We consider
sheet-like structures resulting from cosmological simulations, which were
previously used to establish the cluster mass determination method, and we show
through their level of equilibration, that these structures have indeed only
collapsed along the one dimension. We also extract the density profiles of
these pancake, which agrees acceptably well with theoretical expectations. We
derive the observable velocity distribution function (VDF) analytically by
generalizing the Eddington method to one dimension, and we compare with the
distribution function from the numerical simulation.
