The Cox Ring of a Del Pezzo Surface Has Rational Singularities
Abstract
Description
For a smooth Del Pezzo surface the direct sum of global sections of all isomorphism classes of invertible sheaves on it can be almost canonically endowed with a ring structure, called the Cox ring. We show that in characteristic 0 this ring is Gorenstein and its spectrum has rational singularities. Also a gap in math.AG/0309111 is pointed out.
12 pages, LateX, uses XY-Pic
12 pages, LateX, uses XY-Pic