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arXiv 1208.3909math.AGmath.NT
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三点Galois覆盖的好约化

Good reduction of three-point Galois covers

Andrew Obus

摘要:

Michel Raynaud给出了定义在p-adic域K上的三点G-覆盖f:Y \rightarrow X = P^1具有好约化的准则。特别地,若G的p-Sylow子群的阶为p,且p阶元素的共轭类数大于K的绝对分歧指数e,则f有潜在的好约化.我们给出了不同的证明这个标准,它延伸到的情况下,G有一个任意大的循环p-Sylow子群,回答了一个问题的雷诺。然后,我们使用的标准,给一个家庭的例子,三点覆盖好约化的特征p和任意大的p-Sylow子群。

英文摘要:

Michel Raynaud gave a criterion for a three-point G-cover f : Y \rightarrow X = P^1, defined over a p-adic field K, to have good reduction. In particular, if the order of a p-Sylow subgroup of G is p, and the number of conjugacy classes of elements of order p is greater than the absolute ramification index e of K, then f has potentially good reduction. We give a different proof of this criterion, which extends to the case where G has an arbitrarily large cyclic p-Sylow subgroup, answering a question of Raynaud. We then use the criterion to give a family of examples of three-point covers with good reduction to characteristic p and arbitrarily large p-Sylow subgroups.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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