Rachel Pries, Hui June Zhu
Published 2006-09-22, updated 2010-12-21Version 3
We study a moduli space AS_g for Artin-Schreier curves of genus g over an algebraically closed field k of characteristic p. We study the stratification of AS_g by p-rank into strata AS_{g,s} of Artin-Schreier curves of genus g with p-rank exactly s. We enumerate the irreducible components of AS_{g,s} and find their dimensions. As an application, when p=2, we prove that every irreducible component of the moduli space of hyperelliptic k-curves with genus g and 2-rank s has dimension g-1+s. We also determine all pairs (p,g) for which AS_g is irreducible. Finally, we study deformations of Artin-Schreier curves with varying p-rank. Keywords: Artin-Schreier, hyperelliptic, curve, moduli, p-rank.
Comments: Revisions made in Section 3 and new result added
The $p$-rank stratification of the moduli space of double covers of a fixed elliptic curve
The boundary of the $p$-rank $0$ stratum of the moduli space of cyclic covers of the projective line
On invariants of Artin-Schreier curves
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