Bulletin of the Iranian Mathematical Society

Bulletin of the Iranian Mathematical Society

Finite groups with three relative commutativity degrees

Document Type : Research Paper

Authors
Ferdowsi University of Mashhad
Abstract
‎‎For a finite group $G$ and a subgroup $H$ of $G$‎, ‎the relative commutativity degree of $H$ in $G$‎, ‎denoted by $d(H,G)$‎, ‎is the probability that an element of $H$ commutes with an element of $G$‎. ‎Let $mathcal{D}(G)={d(H,G):Hleq G}$ be the set of all relative commutativity degrees of subgroups of $G$‎. ‎It is shown that a finite group $G$ admits three relative commutativity degrees if and only if $G/Z(G)$ is a non-cyclic group of order $pq$‎, ‎where $p$ and $q$ are primes‎. ‎Moreover‎, ‎we determine all the relative commutativity degrees of some known groups‎.
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  • Receive Date 18 July 2011
  • Revise Date 27 January 2012
  • Accept Date 12 April 2012