English

A class of singularity of arbitrary pairs and log canonicalizations

Algebraic Geometry 2019-05-27 v4

Abstract

We define a class of singularity on arbitrary pairs of a normal variety and an effective R\mathbb{R}-divisor on it, which we call pseudo-lc in this paper. This is a generalization of the usual lc singularity of pairs and log canonical singularity of normal varieties introduced by de Fernex and Hacon. By giving examples of pseudo-lc pairs which are not lc or log canonical in the sense of de Fernex--Hacon's paper, we show that pseudo-lc singularity is a strictly extended notion of those singularities. We prove that pseudo-lc pairs admit a small lc modification. We also discuss a criterion of log canonicity.

Keywords

Cite

@article{arxiv.1804.06326,
  title  = {A class of singularity of arbitrary pairs and log canonicalizations},
  author = {Kenta Hashizume},
  journal= {arXiv preprint arXiv:1804.06326},
  year   = {2019}
}

Comments

33 pages, v4: Remark 4.15 was added, the references are updated, typos are corrected. To appear in Asian J. Math