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Wildly ramified covers with large genus

Rachel Pries
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Abstract

We study wildly ramified G-Galois covers $\phi:Y \to X$ branched at B (defined over an algebraically closed field of characteristic p). We show that curves Y of arbitrarily high genus occur for such covers even when G, X, B and the inertia groups are fixed. The proof relies on a Galois action on covers of germs of curves and formal patching. As a corollary, we prove that for any nontrivial quasi-p group G and for any sufficiently large integer $\sigma$ with $p \nmid \sigma$, there exists a G-Galois \'etale cover of the affine line with conductor $\sigma$ above the point $\infty$.

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Rachel Pries. 2005-07-13. Wildly ramified covers with large genus. https://arxiv.org/abs/math/0507274

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