  Dinamical Friction Problem is a long-standing dilemma about globular
clusters(hereafter,GCs) belonging to dwarf galaxies. The GCs are strongly
affected by dynamical friction in dwarf galaxies, and presumed to fall into the
galactic center. But GCs do exist in dwarf galaxies. Recentry, a new solution
was proposed. If dwarf galaxies have a cored dark matter halo, in which case
the effect of dynamical friction will be weaken considerably, and GCs are able
to survive beyond the age of the universe. In this study, we discussed why does
a constant density cored halo cease dynamical friction, by means of N-body
simulations.
