Independent transversals versus transversals

Abstract

We compare the minimum size of a vertex cover, feedback vertex set and odd cycle transversal of a graph with the minimum size of the corresponding variants in which the transversal must be an independent set. We investigate for which graphs H the two sizes are equal whenever the graph in question belongs to the class of H-free graphs. We find complete classifications for vertex cover and almost complete classifications for feedback vertex set and odd cycle transversal.