The flag Hilbert scheme of points of nodal curves and the punctual Hilbert scheme of points of the cusp curve.

摘要

We study the relative full-flag Hilbert scheme of a family of curves, parameterizing chains of subschemes, containing a node. We will prove that the relative full flag Hilbert scheme is normal with locally complete intersection singularities. We also study the Hilbert scheme of points of the cusp curve and show the punctual Hilbert scheme is isomorphic to P1 . We will see the Hilbert scheme has only one singularity along the punctual one.