The minimal formal models of curve singularities
The minimal formal models of curve singularities
复制标题
曲线奇点的最小形式模型
DOI:
10.1142/s0129167x17500811
复制
发表时间:
2017
影响因子:
0.6
通讯作者:
J. Sebag
中科院分区:
文献类型:
--
作者:
David Bourqui;J. Sebag
Let k be a field. We introduce a new geometric invariant, namely the minimal formal models, associated with every curve singularity (defined over k). This is a noetherian affine adic formal k-scheme, defined by using the formal neighborhood in the associated arc scheme of a primitive k-parametrization. For the plane curve A2n-singularity, we show that this invariant is Spf(k[[Z]]/〈Zn+1〉). We also obtain information on the minimal formal model of the so-called generalized cusp. We introduce various questions in the direction of the study of these minimal formal models with respect to singularity theory. Our results provide the first positive elements of answer. As a direct application of the former results, we prove that, in general, the isomorphisms satisfying the Drinfeld–Grinberg–Kazhdan theorem on the structure of the formal neighborhoods of arc schemes at non-degenerate arcs do not come from the jet levels. In some sense, this shows that the Drinfeld–Grinberg–Kazhdan theorem is not a formal consequenc...