Suspension
The Join of a Topological Space 
and a pair of points 
, 
.
References
Rolfsen, D. Knots and Links. Wilmington, DE: Publish or Perish Press, p. 6, 1976.
- Jacobi's Curvature Theorem
- Jacobi's Determinant Identity
- Jacobi's Imaginary Transformation
- Jacobi's Theorem
- Jacobi Symbol
- Jacobi Tensor
- Jacobi Theta Function
- Jacobi Transformation
- Jacobi Triple Product
- Jacobi Zeta Function
- Jacobsthal-Lucas Number
- Jacobsthal-Lucas Polynomial
- Jacobsthal Number
- Jacobsthal Polynomial
- Jaco-Shalen-Johannson Torus Decomposition
- Janko Groups
- Japanese Triangulation Theorem
- Jarnick's Inequality
- j-Conductor
- Jeep Problem
- Jenkins-Traub Method
- Jensen Polynomial
- Jensen's Formula
- Jensen's Inequality
- Jerabek's Hyperbola