# Tabulation of Cubic Function Fields Via Polynomial Binary Cubic Forms

1 LFANT - Lithe and fast algorithmic number theory
IMB - Institut de Mathématiques de Bordeaux, Inria Bordeaux - Sud-Ouest
Abstract : We present a method for tabulating all cubic function fields over $\mathbb{F}_{q}(t)$ whose discriminant $D$ has either odd degree or even degree and the leading coefficient of $-3D$ is a non-square in $\mathbb_{q}^*$, up to a given bound $X$ on $|D| = q^{\deg(D)}$. Our method is based on a generalization of Belabas' method for tabulating cubic number fields. The main theoretical ingredient is a generalization of a theorem of Davenport and Heilbronn to cubic function fields, along with a reduction theory for binary cubic forms that provides an efficient way to compute equivalence classes of binary cubic forms. The algorithm requires $O(q^4 X^{1+\epsilon})$ field operations when $D$ has odd degree, and $O(q^5 X^{1+\epsilon})$ when $D$ has even degree. It performs quite well in practice. The algorithm, examples and numerical data for $q=5,7,11,13$ are included.
Document type :
Journal articles

https://hal.inria.fr/inria-00477111
Contributor : Pieter Rozenhart <>
Submitted on : Wednesday, April 28, 2010 - 10:11:20 AM
Last modification on : Tuesday, March 27, 2018 - 5:56:01 PM

### Identifiers

• HAL Id : inria-00477111, version 1
• ARXIV : 1004.4785

### Citation

Pieter Rozenhart, Michael Jacobson Jr., Renate Scheidler. Tabulation of Cubic Function Fields Via Polynomial Binary Cubic Forms. Mathematics of Computation, American Mathematical Society, 2012, 81 (280), pp.2335-2359. ⟨inria-00477111⟩

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