Brieskorn manifold

In mathematics, a Brieskorn manifold or Brieskorn–Phạm manifold, introduced by Egbert Brieskorn (1966, 1966b), is the intersection of a small sphere around the origin with the singular, complex hypersurface studied by Frédéric Pham (1965).

Brieskorn manifolds give examples of exotic spheres,[1][2] for example the Gromoll–Meyer sphere.