Abstract
An extrinsic symmetric space is a submanifold $M\subset V = {\mathbb R}^n$ which is kept invariant by the reflection $s_x$ along every normal space $N_xM$. An extrinsic symmetric subspace is a connected component $M'$ of the intersection $M\cap V'$ for some subspace $V'\subset V$ which is $s_x$-invariant for any $x\in M'$. We give an algebraic charactrization of all such subspaces $V'$.
Citation
Jost Eschenburg. Makiko Sumi Tanaka. "Extrinsic symmetric subspaces." Osaka J. Math. 57 (3) 655 - 661, July 2020.
