A (non-compact) symmetric space is of the form $G/K$, where $G$ is a (non-compact) semisimple Lie group defined over $\mathbb{R}$, and $K$ is a maximal compact subgroup of $G$.
Let $M = G/K$ be a rank-one symmetric space of the noncompact type. There are only three families of rank $1$ symmetric spaces:
hyperbolic $n$-space, corresponding to the Lie group $\operatorname{SO}(n,1)$.
complex hyperbolic $n$-space, corresponding to the Lie group $\operatorname{SU}(n,1)$.
quaternionic hyperbolic $n$-space, corresponding to the Lie group $\operatorname{Sp}(n,1)$.
There is also one exceptional example:
- the Cayley upper half plane, corresponding to the Lie group $F_4^{-20}$.
Now, let $G = NAK$ be the Iwasawa decomposition of $G$. Does anyone know what is the Iwasawa decomposition ($N=?$$N={?}$ and $K=?$$K={?}$) of the four cases 1), 2), 3) and 4)?