Year: 2026
Type: preprint
Abstract: Inspired by the recent preprint of Ellenberg, Libedinsky, Plaza, Simental, and Williamson, we study the geometry of Richardson varieties whose associated Bruhat intervals are boolean posets. We define magic words for a Bruhat interval and prove that for intervals with magic words the associated Richardson variety is a tower of $\mathbb{P}^1$-s. We also prove that the Bruhat intervals consisting of the dyadically well-distributed permutations all have magic words. This gives a new proof that they form a boolean poset.
Source: arXiv (Cornell University)
Author: Elek, Balázs
Language: English
Subfield: Discrete Mathematics and Combinatorics
Field: Mathematics
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7222951826