6 citations · 23 across the 42 of their papers we have counts for
8 papers · 2 filters
On curvature-adapted and proper complex equifocal submaniflds
Naoyuki Koike
In this paper, we investigate a curvature-adapted and proper complex equifocal submanifold in a symmetric space of non-compact type. The class of these submanifolds contains princi…
Examples of a complex hyperpolar actions without singular orbit
Naoyuki Koike
The notion of a complex hyperpolar action on a symmetric space of non-compact type has recently been introduced as counterpart of a hyperpolar action on a symmetric space of compac…
On equifocal submanifolds with non-flat section in symmetric spaces of rank two
Naoyuki Koike
In this paper, we show that there exists no equifocal submanifold with non-flat section in four irreducible simply connected symmetric spaces of compact type and rank two. Also, we…
Homogeneity of proper complex equifocal submanifolds
Naoyuki Koike
In this paper, we show that an irreducible proper complex equifocal submanifold of codimension greater than one in a symmetric space of non-compact type. The proof is performed by…
Hermann type actions on a pseudo-Riemannian symmetric space
Naoyuki Koike
We first investigate the geometry of orbits of the isotropy action on a semi-simple pseudo-Riemannian symmetric space by investigating the complexified action. Next we investigate…
The complexifications of pseudo-Riemannian manifolds and anti-Kaehler geometry
Naoyuki Koike
In this paper, we first define the complexification of a real analytic map between real analytic Koszul manifolds and show that the complexified map is the holomorphic extension of…