Let $k$ be an algebraicallly closed field of characteristic $p\geq 0$ and let $G$ be a linear algebraic group of rank $\ell\geq 1$ over $k$. Let $V$ be a rational finite-dimensional $kG$-module and let $V_g(\mu)$ denote the eigenspace corresponding to the eigenvalue $\mu\in k^*$ of $g \in G$ on $V$. We set $\nu_G(V)=\min\{\dim(V)-\dim(V_g(\mu))| g \in G \setminus Z(G), \mu \in k^*\}$. In this talk we will identify pairs $(G,V)$ of simple simply connected linear algebraic groups and of rational irreducible tensor-indecomposable $kG$-modules with the property that $\nu_G(V)\leq \sqrt{\dim(V)}$. This problem is an extension of the classification result obtained by Guralnick and Saxl for $\nu_G(V)\leq \max\{2,\frac{\sqrt{\dim(V)}}{2}\}$. One motivation for studying such problems is to identify subgroups of linear algebraic groups based on element behaviour.
Start Date
Venue
Online seminar
End Date
Ana Retegan
Ecole Polytechnique Fédérale de Lausanne
Ana_Retegan.pdf404.1 KB
Algebra, Combinatorics and Number Theory