English

Non-rational divisors over non-Gorenstein terminal singularities

Algebraic Geometry 2014-12-03 v1

Abstract

Let (X,o)(X,o) be a germ of a 3-dimensional terminal singularity of index m2m\geq 2. If (X,o)(X,o) has type cAx/4, cD/3-3, cD/2-2, or cE/2, then assume that the standard equation of XX in C4/Zm\mathbb{C}^4/\mathbb{Z}_m is non-degenerate with respect to its Newton diagram. Let π ⁣:YX\pi\colon Y\to X be a resolution. We show that there are not more than 2 non-rational divisors EiE_i, i=1,2i=1,2, on YY such that π(Ei)=o\pi(E_i)=o and discrepancy a(Ei,X)1a(E_i,X)\leq 1. When such divisors exist, we describe them as exceptional divisors of certain blowups of XX and study their birational type.

Keywords

Cite

@article{arxiv.math/0410547,
  title  = {Non-rational divisors over non-Gorenstein terminal singularities},
  author = {D. A. Stepanov},
  journal= {arXiv preprint arXiv:math/0410547},
  year   = {2014}
}

Comments

17 pages, LaTeX2e

R2 v1 2026-07-22T17:11:38.146Z