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arXiv · 1407.6234

Computing in arithmetic groups with Voronoi's algorithm

Oliver Braun·Renaud Coulangeon·Gabriele Nebe·Sebastian Schoennenbeck
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Abstract

We describe an algorithm, meant to be very general, to compute a presentation of the group of units of an order in a (semi)simple algebra over Q. Our method is based on a generalisation of Voronoï's algorithm for computing perfect forms, combined with Bass-Serre theory. It differs essentially from previously known methods to deal with such questions, e.g. for units in quaternion algebras. We illustrate this new algorithm by a series of examples where the computations are carried out completely.

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Oliver Braun, Renaud Coulangeon, Gabriele Nebe, Sebastian Schoennenbeck. 2014-07-23. Computing in arithmetic groups with Voronoi's algorithm. https://arxiv.org/abs/1407.6234

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