Department of Mathematics, Faculty of Science, Shahed University,
Tehran, Iran
Abstract:
A finite group whose all irreducible characters are rational valued is called a rational group.
Using the concept of transversal action, we get a sufficient condition on non Abelian rational groups that guarantees every Sylow 2-subgroup is also rational.
This gives a partial answer to an old conjecture rationality of Sylow 2-subgroup of rational group.