Abstract
In this paper, we show that there exist families of curves (defined over an algebraically closed field k of characteristic p>2) whose Jacobians have interesting p-torsion. For example, for every 0≤f≤g, we find the dimension of the locus of hyperelliptic curves of genus g with p-rank at most f. We also produce families of curves so that the p-torsion of the Jacobian of each fibre contains multiple copies of the group scheme α p . The method is to study curves which admit an action by (ℤ/2)n so that the quotient is a projective line. As a result, some of these families intersect the hyperelliptic locus .
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An erratum to this article is available at http://dx.doi.org/10.1007/s00229-010-0392-y.
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Glass, D., Pries, R. Hyperelliptic curves with prescribed p-torsion. manuscripta math. 117, 299–317 (2005). https://doi.org/10.1007/s00229-005-0559-0
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DOI: https://doi.org/10.1007/s00229-005-0559-0