Complex crowns of Riemannian symmetric spaces and non-compactly causal symmetric spaces
Simon Gindikin and Bernhard Krötz
In this paper we define a distinguished boundary for the complex crowns $\Xi\subseteq G_{\mathbb C} /K_{\mathbb C}$ of non-compact Riemannian symmetric spaces $G/K$. The basic result is that affine symmetric spaces of $G$ can appear as a component of this boundary if and only if they are non-compactly causal symmetric spaces.