Extending characters from Hall subgroups.
Gunter Malle, Gabriel Navarro · Documenta Mathematica · 2011
Suppose that G is a finite \pi -separable group. A classical result asserts that all irreducible characters of a Hall \pi -subgroup H of G extend to G if and only if H has a normal complement in G . Now, we fix a prime p and analyze when only the p' -degree irreducible characters of H extend to G .