抄録
Ruled real hypersurfaces in a nonflat complex space form $\widetilde{M}$n(c) (n ≥ 2) are obtained by having a one-codimensional foliation whose leaves are totally geodesic complex hypersurfaces of the ambient space. Motivated by a fact that the sectional curvature K of every ruled real hypersurface M in $\widetilde{M}$n(c) (n ≥ 3) satisfies |c/4| ≤ |K(X, Y)| ≤ |c| for an arbitrary pair of orthonormal vectors X and Y that are tangent to the leaf at each point x of M, we study ruled real hypersurfaces having the sectional curvature K with |c/4| ≤ |K| ≤ |c| in $\widetilde{M}$n(c).