Modular invariants for genus 3 hyperelliptic curves

Sorina Ionica*, Pinar Kilicer, Kristin Lauter, Elisa Lorenzo Garcia, Maike Massierer, Adelina Manzateanu, Christelle Vincent

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Scopus)
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In this article we prove an analogue of a theorem of Lachaud, Ritzenthaler, and Zykin, which allows us to connect invariants of binary oc-tics to Siegel modular forms of genus 3. We use this connection to show that certain modular functions, when restricted to the hyperelliptic locus, assume values whose denominators are products of powers of primes of bad reduction for the associated hyperelliptic curves. We illustrate our theorem with explicit computations. This work is motivated by the study of the value of these modular functions at CM points of the Siegel upper-half space, which, if their denominators are known, can be used to effectively compute models of (hyperelliptic, in our case) curves with CM.
Original languageEnglish
Number of pages22
JournalResearch in Number Theory
Issue number9
Publication statusPublished - 2-Jan-2019


  • math.NT

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