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arXiv · 1403.4725

Ziegler's Multi-Reflection Arrangements are free

Torsten Hoge·Gerhard Roehrle
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Abstract

In 1989, Ziegler introduced the concept of a multi-arrangement. One natural example is the reflection arrangement of a unitary reflection group with multiplicity given by the number of reflections associated with each hyperplane. For all but three irreducible groups, Ziegler showed that each such multi-reflection arrangement is free. We complete Ziegler's example by confirming these outstanding cases.

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Torsten Hoge, Gerhard Roehrle. 2014-06-27. Ziegler's Multi-Reflection Arrangements are free. https://arxiv.org/abs/1403.4725

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