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arXiv · 2502.02274

Hyperpolygonal arrangements

Lorenzo Giordani·Paul Mücksch·Gerhard Roehrle·Johannes Schmitt
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Abstract

In 2024, Bellamy, Craw, Rayan, Schedler, and Weiss introduced a particular family of real hyperplane arrangements stemming from hyperpolygonal spaces associated with certain quiver varieties which we thus call hyperpolygonal arrangements $\mathcal H_n$. In this note we study these arrangements and investigate their properties systematically. Remarkably the arrangements $\mathcal H_n$ discriminate between essentially all local properties of arrangements. In addition we show that hyperpolygonal arrangements are projectively unique and combinatorially formal. We note that the arrangement $\mathcal H_5$ is the famous counterexample of Edelman and Reiner from 1993 of Orlik's conjecture that the restriction of a free arrangement is again free.

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Lorenzo Giordani, Paul Mücksch, Gerhard Roehrle, Johannes Schmitt. 2025-02-04. Hyperpolygonal arrangements. https://doi.org/10.1017/s0017089525100633

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