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arXiv · 2605.19880

Subarrangements of type A: the weak Lefschetz property of the Artinian Orlik-Terao algebra

Nicholas Gaubatz·Hal Schenck
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Abstract

In 1994, Orlik and Terao introduced a commutative Artinian analog S/I(A) of the Orlik-Solomon algebra of a hyperplane arrangement A to answer a question of Aomoto. A central topic of investigation in the study of Artinian algebras is the Weak Lefschetz Property (WLP). We analyze WLP for the Artinian Orlik-Terao algebra of graphc arrangements. Even for chordal graphs (which give rise to Koszul algebras) WLP sometimes fails; conversely an analysis of the state polytope shows WLP can hold even when WLP fails for all possible initial ideals. More generally, for any algebra with a tensor product decomposition, we construct canonical elements in the kernel of the multiplication map, refining previous results in the literature.

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Nicholas Gaubatz, Hal Schenck. 2026-05-19. Subarrangements of type A: the weak Lefschetz property of the Artinian Orlik-Terao algebra. https://arxiv.org/abs/2605.19880

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