Critical groups of generalized de Bruijn and Kautz graphs and circulant matrices over finite fields: an extended abstract

We determine the critical groups of the generalized de Bruijn graphs DB$(n,d)$ and generalized Kautz graphs Kautz$(n,d)$, thus extending and completing earlier results for the classical de Bruijn and Kautz graphs. Moreover, for a prime $p$ the critical groups of DB$(n,p)$ are shown to be in close correspondence with groups of $n\times n$ circulant matrices over ${\mathbb{F}}_p$, which explains numerical data in [OEIS:A027362], and suggests the possibility to construct normal bases in ${\mathbb{F}}_{p^n}$ from spanning trees in DB$(n,p)$.