On reductive subgroups of reductive groups having invariants in almost all representations

Valdemar Tsanov, Yana Staneva

Let $G$ and $\tilde{G}$ be connected complex reductive Lie groups, $G$ semisimple. Let ${\Lambda }^{+}$ be the monoid of dominant weights for a positive root system ${\Delta }^{+}$, and let $l(w)$ be th…