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arXiv · 1006.4381

Computing generators of free modules over orders in group algebras II

Werner Bley·Henri Johnston
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Abstract

Let E be a number field and G be a finite group. Let A be any O_E-order of full rank in the group algebra E[G] and X be a (left) A-lattice. In a previous article, we gave a necessary and sufficient condition for X to be free of given rank d over A. In the case that (i) the Wedderburn decomposition of E[G] is explicitly computable and (ii) each component is in fact a matrix ring over a field, this led to an algorithm that either gives elements that either gives an A-basis for X or determines that no such basis exists. In the present article, we generalise the algorithm by weakening condition (ii) considerably.

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Werner Bley, Henri Johnston. 2010-06-22. Computing generators of free modules over orders in group algebras II. https://arxiv.org/abs/1006.4381

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