In mathematics, a Brieskorn manifold or Brieskorn–Phạm manifold, introduced by Egbert Brieskorn, is the intersection of a small sphere around the origin with the singular, complex hypersurface x 1 k 1 + ⋯ + x n k n = 0 {\displaystyle x_{1}^{k_{1}}+\cdots +x_{n}^{k_{n}}=0} studied by Frédéric Pham. Wikipedia