English

On the Lefschetz Property for quotients by monomial ideals containing squares of variables

Commutative Algebra 2024-03-12 v4 Combinatorics

Abstract

Let Δ\Delta be an (abstract) simplicial complex on nn vertices. One can define the Artinian monomial algebra A(Δ)=k[x1,,xn]/x12,,xn2,IΔA(\Delta) = \Bbbk[x_1, \ldots, x_n]/ \langle x_1^2, \ldots, x_n^2, I_{\Delta} \rangle, where k\Bbbk is a field of characteristic 00 and IΔI_\Delta is the Stanley-Reisner ideal associated to Δ\Delta. In this paper, we aim to characterize the Weak Lefschetz Property (WLP) of A(Δ)A(\Delta) in terms of the simplicial complex Δ\Delta. We are able to completely analyze when WLP holds in degree 11, complementing work by Migliore, Nagel and Schenck in [MNS2020]. We give a complete characterization of all 22-dimensional pseudomanifolds Δ\Delta such that A(Δ)A(\Delta) satisfies WLP. We also construct Artinian Gorenstein algebras that fail WLP by combining our results and the standard technique of Nagata idealization.

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Cite

@article{arxiv.2112.09434,
  title  = {On the Lefschetz Property for quotients by monomial ideals containing squares of variables},
  author = {Hailong Dao and Ritika Nair},
  journal= {arXiv preprint arXiv:2112.09434},
  year   = {2024}
}

Comments

13 pages, 3 figures