An Improvement of de Jong-Oort's Purity Theorem
Algebraic Geometry
2010-04-20 v1
Abstract
Consider an -crystal over a noetherian scheme . De Jong--Oort's purity theorem states that the associated Newton polygons over all points of are constant if this is true outside a subset of codimension bigger than 1. In this paper we show an improvement of the theorem, which says that the Newton polygons over all points of have a common break point if this is true outside a subset of codimension bigger than 1.
Cite
@article{arxiv.1004.3090,
title = {An Improvement of de Jong-Oort's Purity Theorem},
author = {Yanhong Yang},
journal= {arXiv preprint arXiv:1004.3090},
year = {2010}
}