非本原复反射群 $G(r,1,n)$ 的 Specht 理想:几何轨道类型与支配定理
Specht ideals for the imprimitive complex reflection group $G(r,1,n)$: geometric orbit types and a dominance theorem
浏览论文内容
中文总结 AI 辅助
本文为非本原复反射群 $G(r,1,n)$ 构造 Specht 理想,以几何不变量对 $(\mu,z)$ 上的支配序刻画理想与簇包含关系,并恢复经典 $B_n$ 情形。
中文摘要 AI 辅助
Moustrou、Riener 和 Verdure 将划分上的支配序与 $S_n$ 的 Specht 理想及簇包含联系起来;我们先前将其推广到对称群的直积。此处我们迈出对非本原复反射群 $G(r,1,n)=(\mathbb{Z}/r\mathbb{Z})\wr S_n$ 的第一步。点 $x\in K^n$ 的正确几何不变量是一对 $(\mu,z)$:非零坐标的 $r$ 次幂上的经典划分 $\mu$,以及零坐标的个数 $z$。我们为每一对这样的 $(\mu,z)$ 构造一个 $G(r,1,n)$-不变理想 $I_{(\mu,z)}$,并证明在 $(\mu,z)$ 上的支配序(其中 $z$ 严格优先于 $\mu$)恰好刻画了理想包含和反向簇包含。我们在三个区域中解决了一个单项式准则,在 $r=2$ 且 $z=0$ 时恢复了经典的 $B_n$-Specht 理想理论,并在 $z=0$ 层的两个极端情形下确立了 $I_{(\mu,z)}$ 的根性。四个计算实例(经穷举检查群不变性)贯穿说明了该构造。
英文摘要
Moustrou, Riener, and Verdure related the dominance order on partitions to Specht ideal and variety inclusion for $S_n$; we previously extended this to direct products of symmetric groups. Here we take a first step toward the imprimitive complex reflection group $G(r,1,n)=(\mathbb{Z}/r\mathbb{Z})\wr S_n$. The correct geometric invariant of a point $x\in K^n$ is a pair $(μ,z)$: a classical partition $μ$ on the $r$-th powers of the nonzero coordinates, together with the number $z$ of zero coordinates. We construct a $G(r,1,n)$-invariant ideal $I_{(μ,z)}$ for each such pair, and show that a dominance order on $(μ,z)$, with $z$ taking strict priority over $μ$, exactly characterizes both ideal inclusion and reverse variety inclusion. We settle a monomial criterion in three regimes, recover the classical $B_n$-Specht ideal theory at $r=2$ when $z=0$, and establish radicality of $I_{(μ,z)}$ at the two extremes of the $z=0$ level. Four computational examples, checked exhaustively for group invariance, illustrate the construction throughout.