by
Alvaro Liendo, Hendrik Süß
Abstract:
We propose a method to compute a desingularization of a normal affine variety X endowed with a torus action in terms of a combinatorial description of such a variety due to Altmann and Hausen. This desingularization allows us to study the structure of the singularities of X. In particular, we give criteria for X to have only rational, (Q-)factorial, or (Q-)Gorenstein singularities. We also give partial criteria for X to be Cohen-Macaulay or log-terminal. Finally, we provide a method to construct factorial affine varieties with a torus action. This leads to a full classification of such varieties in the case where the action is of complexity one.
Reference:
Normal singularities with torus actions (Alvaro Liendo, Hendrik Süß), Tohoku Mathematical Journal, volume 65, 2013.
Bibtex Entry:
@article{tsing,
author = {{Liendo}, Alvaro and {S{\"u}{\ss}}, Hendrik},
title = "{Normal singularities with torus actions}",
doi={10.2748/tmj/1365452628},
journal = {Tohoku Mathematical Journal},
archivePrefix = "arXiv",
eprint = {1005.2462},
primaryClass = "math.AG",
keywords = {Mathematics - Algebraic Geometry, 14L30, 14B05, 14M25},
year = 2013,
month = jan,
pages = {105-130} ,
volume = 65,
issue = 1,
url = {http://arxiv.org/abs/1005.2462},
gsid={13924844087682941334},
abstract = {We propose a method to compute a desingularization of a normal affine variety X endowed with a torus action in terms of a combinatorial description of such a variety due to Altmann and Hausen. This desingularization allows us to study the structure of the singularities of X. In particular, we give criteria for X to have only rational, (Q-)factorial, or (Q-)Gorenstein singularities. We also give partial criteria for X to be Cohen-Macaulay or log-terminal. Finally, we provide a method to construct factorial affine varieties with a torus action. This leads to a full classification of such varieties in the case where the action is of complexity one. },
}