Regular polytopes of rank $n/2$ for transitive groups of degree $n$

Maria Elisa Fernandes, Claudio Alexandre Piedade

Published 2024-07-22Version 1

Previous research established that the maximal rank of the abstract regular polytopes whose automorphism group is a transitive proper subgroup of $\Sym_n$ is $n/2 + 1$, with only two polytopes attaining this rank, both of which having odd ranks. In this paper, we investigate the case where the rank is equal to $n/2$ ($n\geq 14$). Our analysis reveals that reducing the rank by one results in a substantial increase in the number of regular polytopes ($33$ distinct families are discovered) covering all possible ranks (even and odd).