Plumbing
The plumbing of a p-sphere and a q-sphere is defined as the disjoint union of S^p×D^q and D^p×S^q with their common D^p×D^q, identified via the identity homeomorphism.
This is a special case of a more general type of plumbing whereby disk bundles are fused together (Rolfsen 1976, p. 180).
See also
HypersphereExplore with Wolfram|Alpha
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References
Rolfsen, D. Knots and Links. Wilmington, DE: Publish or Perish Press, p. 180, 1976.Referenced on Wolfram|Alpha
PlumbingCite this as:
Weisstein, Eric W. "Plumbing." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Plumbing.html