The Redshift Evolution of LCDM Halo Parameters: Concentration, Spin, and
  Shape
  We present a detailed study of the redshift evolution of dark matter halo
structural parameters in a LambdaCDM cosmology. We study the mass and redshift
dependence of the concentration, shape and spin parameter in Nbody simulations
spanning masses from 10^{10} Msun/h to 10^{15} Msun/h and redshifts from 0 to
2. We present a series of fitting formulas that accurately describe the time
evolution of the concentration-mass relation since z=2. Using arguments based
on the spherical collapse model we study the behaviour of the scale length of
the density profile during the assembly history of haloes, obtaining physical
insights on the origin of the observed time evolution of the concentration mass
relation. We also investigate the evolution with redshift of dark matter halo
shape and its dependence on mass. Within the studied redshift range the
relation between halo shape and mass can be well fitted by a power law. Finally
we show that although for z=0 the spin parameter is practically mass
independent, at increasing redshift it shows a increasing correlation with
mass.
