Groups generated by k-transvections.
Let be a finite group and write for the degree set of the complex irreducible characters of . The group is said to satisfy the two-prime hypothesis if for any distinct degrees , the total number of (not necessarily different) primes of the greatest common divisor is at most . We prove an upper bound on the number of irreducible character degrees of a nonsolvable group that has a composition factor isomorphic to PSL for .