Shifted lower Bruhat intervals are EL-shellable

Aman Dave, Taiwen Feng, Nathan Lesnevich +4

Let $W$ be an arbitrary Coxeter group. The shifted Bruhat interval $[w_1,w_2]x^{-1}$, the translate of the Bruhat interval $[w_1,w_2]$ by an element $x$, is partially ordered by…