Kernels in circulant digraphs

Abstract

A kernel $J$ of a digraph $D$ is an independent set of vertices of $D$ such that for every vertex $w,in,V(D),setminus,J$ there exists an arc from $w$ to a vertex in $J.$‎ ‎In this paper‎, ‎among other results‎, ‎a characterization of $2$-regular circulant digraph having a kernel is obtained‎. ‎This characterization is a partial solution to the following problem‎: ‎Characterize circulant digraphs which have kernels; it appeared in the book <em>Digraphs‎ - ‎theory‎, ‎algorithms and applications</em>‎, ‎Second Edition‎, ‎Springer-Verlag‎, ‎2009‎, ‎by J‎. ‎Bang-Jensen and G‎. ‎Gutin‎.