Groups whose degree graph has three independent vertices

Let G be a finite group, and let cd(G) denote the set of degrees of the irreducible complex characters of G. This paper is a contribution to the study of the degree graph of G, that is, the prime graph built on the set cd(G). Namely, we characterize finite groups whose degree graph has three independent vertices (i.e., three vertices that are pairwise non-adjacent). Our result turns out to be a generalization of several previously-known theorems concerning the structure of the degree graph.