University of IsfahanInternational Journal of Group Theory2251-76502220130601Character expansiveness in finite groups917166010.22108/ijgt.2013.1660ENZoltan HalasiUniversity of DebrecenAttila MarotiRenyi Institute of MathematicsFranciska PetenyiTechnical University of BudapestJournal Article20120606We say that a finite group $G$ is conjugacy expansive if for any normal subset $S$ and any conjugacy class $C$ of $G$ the normal set $SC$ consists of at least as many conjugacy classes of $G$ as $S$ does. Halasi, Mar'oti, Sidki, Bezerra have shown that a group is conjugacy expansive if and only if it is a direct product of conjugacy expansive simple or abelian groups. By considering a character analogue of the above, we say that a finite group $G$ is character expansive if for any complex character $alpha$ and irreducible character $chi$ of $G$ the character $alpha chi$ has at least as many irreducible constituents, counting without multiplicity, as $alpha$ does. In this paper we take some initial steps in determining character expansive groups.http://ijgt.ui.ac.ir/article_1660_4335a14289e50a35e7186085ea9a408c.pdf