Even Factors in Digraphs

Professor Bill Cunningham

ABSTRACT

An even factor in a digraph is a set of even cycles including each vertex exactly once. If the digraph is symmetric, then it has an even factor if and only if the underlying undirected graph has a perfect matching. I will describe results on even factors that extend basic results on matching, and will also indicate some limitations, some useful techniques, and some further generalizations. This is based on joint work with Jim Geelen.