Two examples of surfaces with normal crossing singularities
Algebraic Geometry
2007-08-26 v2
Abstract
This note gives two examples of surfaces with normal crossing singularities. In the first example the canonical ring is not finitely generated. In the second, the canonical line bundle is not ample but its pull back to the normalization is ample. The latter answers in the negative a problem left unresolved in [EGA,III.2.6.2] and raised again by Viehweg.
Cite
@article{arxiv.0705.0926,
title = {Two examples of surfaces with normal crossing singularities},
author = {János Kollár},
journal= {arXiv preprint arXiv:0705.0926},
year = {2007}
}