  Using weakly nonlinear conditional PDF for the density field around an
overdense region we find that the expected density contrast around a peak is
always smaller while its rms fluctuation larger than in the linear case. We
apply these results to the spherical model of collapse as developed by Hoffman
& Shaham (1985) and find that in the case of open Universe the effect of weakly
nonlinear interactions is to decrease the scale from which a peak gathers mass
and the mass itself as well as to steepen the final profile of the virialized
protoobject.
