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Somnath Basu
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Bob Yuncken
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In a compact lie group, can two closed connected subgroups generate a non-closed subgroup?

Let $H$,$K$ be closed connected subgroups of a compact Lie group $G$. Let $L:=\langle H,K \rangle$ be the subgroup they generate, ie, the smallest subgroup of $G$ containing them both. Must $L$ be closed?

Notes:

  1. False if $G$ is not compact.

  2. False if $H$, $K$ not connected: consider two $\mathbb{Z}/2\mathbb{Z}$ subgroups in $O(2)$ generated by reflections in irrationally related axes.

Is there a way to jack up (2) to a connected counterexample, for instance?