Cyclic Derangements

Abstract

A classic problem in enumerative combinatorics is to count the number of derangements, that is, permutations with no fixed point. Inspired by a recent generalization to facet derangements of the hypercube by Gordon and McMahon, we generalize this problem to enumerating derangements in the wreath product of any finite cyclic group with the symmetric group. We also give $q$- and $(q,t)$-analogs for cyclic derangements, generalizing results of Gessel, Brenti and Chow.