Covers of rational double points in mixed characteristic

Autor: Karl Schwede, Linquan Ma, Thomas Polstra, Kevin Tucker, Javier Carvajal-Rojas
Rok vydání: 2021
Předmět:
Zdroj: Journal of Singularities. 23
ISSN: 1949-2006
DOI: 10.5427/jsing.2021.23h
Popis: We further the classification of rational surface singularities. Suppose $(S, \mathfrak{n}, \mathcal{k})$ is a strictly Henselian regular local ring of mixed characteristic $(0, p > 5)$. We classify functions $f$ for which $S/(f)$ has an isolated rational singularity at the maximal ideal $\mathfrak{n}$. The classification of such functions are used to show that if $(R, \mathfrak{m}, \mathcal{k})$ is an excellent, strictly Henselian, Gorenstein rational singularity of dimension $2$ and mixed characteristic $(0, p > 5)$, then there exists a split finite cover of $\mbox{Spec}(R)$ by a regular scheme. We give an application of our result to the study of $2$-dimensional BCM-regular singularities in mixed characteristic.
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Databáze: OpenAIRE