Accompanying electronic reference for Visualising Sha[2] in Abelian Surfaces

This page contains the scripts and their output that were used to compute the examples 1 through 4 in the article

Nils Bruin, Visualising Sha[2] in Abelian Surfaces, 2002.

For people who have access to MAGMA 2.9, it is possible to download the package Algaem and do the computations for themselves. Other people can still read the supplied output files to get an idea of how the computations were done.

Installation instructions: Download algaem.tgz, gunzip and untar (contact the author if you are unable to do so). This produces a subdirectory Algaem. Use

AttachSpec("Algaem/Algaem.spec");

to get access to the routines.

To run one of the scripts below: Download one of the input scripts. Make sure you put it in the directory where the Algaem subdir resides. Input the lines of the script into MAGMA in the order in which they appear, for instance by

SetEchoInput(true);load "example1.m";

Input script for Example 1 Pregenerated output
Input script for Example 2 Pregenerated output
Input script for Example 3 Pregenerated output
Input script for Example 4 (first part) Pregenerated output
Input script for Example 4 (second part) Pregenerated output