پديدآورندگان :
Akhlaghi Zeinab z akhlaghi@aut.ac.ir Faculty of Math. and Computer Sci., Amirkabir University of Technology (Tehran Polytechnic), 15914 Tehran, Iran , Beltrán Antonio abeltran@mat.uji.es Departamento de Matemá ticas, Universidad Jaume I, 12071 Castellón, Spain , José Felipe María mfelipe@mat.upv.es Abstract Instituto Universitario de Matemá tica Pura y Aplicada, Universidad Polité cnica de Valencia, 46022 Valencia, Spain
چكيده فارسي :
If G is a finite group, we show that any normal subgroup of G which has exactly three Gconjugacy
class sizes is solvable. Th us, we give an extension for normal subgroups of the classical
N. Itˆo’s theorem which asserts that those finite groups which having three class sizes are solvable,
and particularly, a new proof of it is provided.
