hypersphere

For spheres in hyperspace, see n-sphere.

In geometry of higher dimensions, a hypersphere is the set of points at a constant distance from a given point called its center. The surface of the hypersphere is a manifold of one dimension less than the ambient space. As the radius increases the curvature of the hypersphere decreases; in the limit a hypersphere approaches the zero curvature of a hyperplane. Both hyperplanes and hyperspheres are hypersurfaces.