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GROUPS WITH THE SAME CHARACTER DEGREES AS SPORADIC ALMOST SIMPLE GROUPS

Part of: Representation theory of groups

Published online by Cambridge University Press:  23 May 2016

SEYED HASSAN ALAVI ,
ASHRAF DANESHKHAH  and
ALI JAFARI
SEYED HASSAN ALAVI
Affiliation:
Department of Mathematics, Faculty of Science, Bu-Ali Sina University, Hamedan, Iran email [email protected]
ASHRAF DANESHKHAH*
Affiliation:
Department of Mathematics, Faculty of Science, Bu-Ali Sina University, Hamedan, Iran email [email protected], [email protected]
ALI JAFARI
Affiliation:
Department of Mathematics, Faculty of Science, Bu-Ali Sina University, Hamedan, Iran email [email protected]
*
✉[email protected]
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Abstract

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Let $G$ be a finite group and $\mathsf{cd}(G)$ denote the set of complex irreducible character degrees of $G$. We prove that if $G$ is a finite group and $H$ is an almost simple group whose socle is a sporadic simple group $H_{0}$ and such that $\mathsf{cd}(G)=\mathsf{cd}(H)$, then $G^{\prime }\cong H_{0}$ and there exists an abelian subgroup $A$ of $G$ such that $G/A$ is isomorphic to $H$. In view of Huppert’s conjecture, we also provide some examples to show that $G$ is not necessarily a direct product of $A$ and $H$, so that we cannot extend the conjecture to almost simple groups.

Keywords

character degreesalmost simple groupssporadic simple groupsHuppert’s conjecture

MSC classification

Primary: 20C15: Ordinary representations and characters
Secondary: 20D05: Finite simple groups and their classification
Type
Research Article
Information
Bulletin of the Australian Mathematical Society , Volume 94 , Issue 2 , October 2016 , pp. 254 - 265
Copyright
© 2016 Australian Mathematical Publishing Association Inc. 

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