发表机构
Sabanci University; Purdue University(萨贝里大学; 普渡大学)
机构由 AI 辅助整理,请以论文原文为准。AI 中文总结
该研究定义了多立方体理想,证明三维及以上时该理想为素理想当且仅当多立方体是长方体,刻画了均匀厚度凸多立方体的Cohen-Macaulay性质,并应用于证明加厚L-凸多联骨牌的多立方体代数是Koszul代数。
AI 中文摘要
对于欧氏空间Rⁿ中的一个多立方体𝒫,我们将其与一个理想I_𝒫关联,该理想由𝒫的长方体顶点的并-交关系生成。当n=2时,这些理想即为多联骨牌理想。与平面情形不同,我们证明当n≥3时,理想I_𝒫为素理想当且仅当𝒫是一个长方体。对于R³中均匀厚度的凸多立方体,其顶点集为ℕ³的一个子格,其定义关系构成二次格罗比纳基,我们通过𝒫顶点上的偏序集刻画了这些多立方体的Cohen-Macaulay性质;在该情形下,偏序集的序复形是顶点可分解的。最后作为应用,我们证明加厚L-凸多联骨牌的多立方体代数是Koszul代数,并刻画了其为Cohen-Macaulay代数的条件。
英文摘要
To a polycube $\mathcal P$ in $\mathbb R^n$, we associate an ideal $I_{\mathcal P}$ generated by the join--meet relations of vertices that are corners of a cuboid of $\mathcal P$. For $n=2$ these are the polyomino ideals. In contrast with the planar case, we show that for $n\geq 3$ the ideal $I_{\mathcal P}$ is prime if and only if $\mathcal P$ is a cuboid. For convex polycubes in $\mathbb R^3$ of uniform thickness whose vertex set is a sublattice of $\mathbb N^3$, the defining relations form a quadratic Gröbner basis, and we characterize the Cohen--Macaulay ones in terms of a poset on the vertices of $\mathcal P$; in this case the order complex of the poset is vertex decomposable. Finally, as an application, we show that the polycube algebra of a thickened $L$-convex polyomino is Koszul, and we characterize when it is Cohen--Macaulay.
Comments28 pages, 13 figures