Loading...
Counting Real Conjugacy Classes in Some Finite Classical Groups
Amparo, Elena
Amparo, Elena
Abstract
An element $g$ in a group $G$ is real if there exists $x\in G$ such that $xgx^{-1}=g^{-1}$. If $g$ is real then all elements in the conjugacy class of $g$ are real. In \cite{GS1} and \cite{GS2}, Gill and Singh showed that the number of real $\mathrm{GL}_n(q)$-conjugacy classes contained in $\mathrm{SL}_n(q)$ equals the number of real $\mathrm{PGL}_n(q)$-conjugacy classes when $q$ is even or $n$ is odd. In this paper, we use generating functions to show that the result is also true for odd $q$. We then follow the methods of \cite{GS1} and \cite{GS2} to count the number of real $\mathrm{U}_n(q)$ conjugacy classes contained in $\mathrm{SU}_n(q)$ and the number of real conjugacy classes in $\mathrm{PGU}_n(q)$, and we show that these are equal to the analogous quantities for $\mathrm{GL}_n(q)$ and $\mathrm{PGL}_n(q)$. Thus, we show that these four sets of conjugacy classes have equal size for all $n,q$.
Description
Date
2018-05-01
Journal Title
Journal ISSN
Volume Title
Publisher
Collections
Download Dataset
Rights Holder
Usage License
Embargo
Research Projects
Organizational Units
Journal Issue
Keywords
Citation
Department
Mathematics