Please send comments and bugs to ritzenth(at)iml.univ-mrs.fr

This is a work in collaboration with Reynald Lercier and Jeroen Sijsling. It has been implemented in Magma (v.2.17). You can download the .tgz here.

This is a work in collaboration with Reynald Lercier. It has been implemented in Magma (v.2.17). You can download the .tgz here.

This is a work in collaboration with R. Lercier. It has been implemented in Magma (v.2.13) and is part of the current Magma distribution. You can also download the .tgz here.

The construction takes place over the field of moduli when there is no obstruction and compute all twists (not only quadratic) over a given finite field.

This is a work in collaboration with M. Fouquet and P. Gaudry. It has been implemented in Magma (v.2.09). You can download the .tgz here.

curve over F_2^N | computation of the initial theta constants | computation of the product of the pi_i with a precision of 10 N | computation of the minimal polynomial with LLL | Signe ; Frobenius polynomial |

N=100 | 65 s | 1mn | 2s | 4s answer |

N=5002 | 34000 s | more or less 2 weeks |
1mn | 27000s answer |

Here are several programs relative to the paper `An explicit expression of Luroth invariant' with Romain Basson, Reynald Lercier and Jeroen Sijsling. This Magma program provides a way to compute an expression of Luroth invariant and this is the final result. This Magma program generates random Luroth quartics of type L_1 (with the notation of Ottaviani, Sernesi `On singular Luroth quartics') and this database contains 10,000 of them with rational coefficients. Finally this program checks that neither L_1 nor L_2 defines a new invariant. Note that they require the use of Echidna package available on this page.

Magma programs to check the computations of `Fast computation of isomorphisms of hyperelliptic curves and explicit descent' with Reynald Lercier and Jeroen Sijsling.

Two programs related to the article on intersection of a line and a quartic :

A program (collaboration with P. Trebuchet) in MAGMA which tests if a plane curve over a finite field is absolutely irreducible. It is based on E. Kaltofen article : Fast parallel absolute irreductibility testing, J. Symb. Comp. 1, (1985), 57-67.

A program in MAGMA which computes the p-rank of the modular curves X(N).

A basic program in MAGMA for computing the number of points on an elliptic curve with AGM as suggested by J.-F. Mestre.