English

Weak Hironaka theorem

alg-geom 2008-02-03 v2 Algebraic Geometry

Abstract

The purpose of this note is to give a simple proof of the following theorem: Let XX be a normal projective variety over an algebraically closed field kk, \opchark=0\op{char} k = 0 and let DXD \subset X be a proper closed subvariety of XX. Then there exist a smooth projective variety MM, a strict normal crossings divisor RMR \subset M and a birational morphism f:MXf : M \to X with f1D=Rf^{-1} D = R. The method of proof is inspired by A.J. de Jong alteration ideas. We also use a multidimensional version of G.Belyi argument which allows us to simplify the shape of a ramification divisor. By induction on the dimension of XX the problem is reduced to resolving toroidal singularities. This process however is too crude and does not permit any control over the structure of the birational map ff. A different proof of the same theorem was found independently by D. Abramovich and A.J. de Jong. The approach is similar in both proofs but they seem to be rather different in details.

Keywords

Cite

@article{arxiv.alg-geom/9603019,
  title  = {Weak Hironaka theorem},
  author = {Fedor Bogomolov and Tony Pantev},
  journal= {arXiv preprint arXiv:alg-geom/9603019},
  year   = {2008}
}

Comments

11 pages, minor corrections, version revised for publication LATEX 2e