A dynamical Shafarevich theorem for rational maps over number fields and function fields
Algebraic Geometry
2017-05-17 v1
Abstract
We prove a dynamical Shafarevich theorem on the finiteness of the set of isomorphism classes of rational maps with fixed degeneracies. More precisely, fix an integer d at least 2 and let K be either a number field or the function field of a curve X over a field k, where k is of characteristic zero or p>2d-2 that is either algebraically closed or finite. Let S be a finite set of places of K. We prove the finiteness of the set of isomorphism classes of rational maps over K with a natural kind of good reduction outside of S. We also prove auxiliary results on finiteness of reduced effective divisors in with good reduction outside of S and on the existence of global models for rational maps.
Keywords
Cite
@article{arxiv.1705.05489,
title = {A dynamical Shafarevich theorem for rational maps over number fields and function fields},
author = {Lucien Szpiro and Lloyd West},
journal= {arXiv preprint arXiv:1705.05489},
year = {2017}
}
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16 pages