Abstract
We study the collapse and evolution of dark matter halos that result from the gravitational instability and fragmentation of cosmological pancakes. Such halos resemble those formed by hierarchical clustering in a CDM universe. Our halos are in approximate virial equilibrium and roughly isothermal, as in CDM simulations. Their evolving density profiles and mass accretion history are very similar to those reported recently in N-body simulations of CDM. We therefore conclude that these properties are a generic result of formation by gravitational instability and are not limited to hierarchical clustering or Gaussian-random-noise initial conditions.
