Non-archimedean orbifolds covered by mumford curves
Non-archimedean orbifolds covered by mumford curves
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DOI:
10.1090/s1056-3911-04-00384-4
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发表时间:
2005
影响因子:
1.8
通讯作者:
Fumiharu Kato
中科院分区:
文献类型:
--
作者:
Fumiharu Kato
In this article we develop a theory of the socalled Mumford orbifolds, viz. rigid-analytic orbifolds covered by Mumford curves. General recipe for treating such orbifolds is given. The main result states a necessary and sufficient condition for abstruct graphs of groups to be realized as discrete groups for Mumford orbifolds, which is useful for constructing several interesting non-archimedean discrete groups, such as p-adic triangle groups.1. Introduction. Like in the classical theory of Riemann surfaces the orbifold technique should be useful also in rigid analytic geometry for studying algebraic/analytic curves. The theory of rigid analytic orbifolds should provide a practical method for studying geometry of curves, especially for analyzing their symmetries (automorphisms) by reflecting them in (ramified) Galois coveringes, which leads for instance to understanding of the stratification of moduli of curves. Moreover, such a theory should be successful also in the theory of linear differential equations, especially in visualizing their monodromy phenomena, as it was the case in the classical setting (cf.[23] for an excellent account). Our objective in this article is to discuss the basic geometry of the so-called Mumford orbifolds, which are perhaps among the most practically important classes of orbifolds in rigid analytic geometry, and the construction of the related discrete groups. Let us be more precise in explaining it: Let K be an algebraically closed complete non-archimedean valued field with a non-trivial valuation. Our notion of orbifold is taken up from the p-adic orbifolds introduced by Yves André (cf.[1, § 5]):