The Bruhat order on conjugation-invariant sets of involutions in the symmetric group

Mikael Hansson

Let $I_n$ be the set of involutions in the symmetric group $S_n$, and for $A\subseteq \{0,1,\dots ,n\}$, let \[ F_n^A=\{σ\in I_n \mid \text{$\sigma$ has $a$ fixed points for some $a \i…