Rooted minors and delta wye transformations

Lino Demasi

A terminal graph G is a graph where some subset of the vertices is distinguished (called terminal vertices). A terminal graph H is said to be a rooted minor of a terminal graph G is we can obtain H as a minor of G such that in the minor, terminal vertices of G correspond to terminal vertices of H. We will look at the problem of determining when a planar graph has a rooted K_2,4 minor and an application of the result to terminal delta-wye reducibility.