Lens Space
A lens space 
is the 3-Manifold obtained by gluing the boundaries of two solid Tori together such that the meridian of the first goes to a 
-curve on the second, where a-curve has 
meridians and 
longitudes.
References
Rolfsen, D. Knots and Links. Wilmington, DE: Publish or Perish Press, 1976.
- Heptagonal Number
- Heptagonal Pyramidal Number
- Heptahedron
- Heptakaidecagon
- Heptaparallelohedron
- Heptomino
- Herbrand's Theorem
- Hereditary Representation
- Heredity
- Hermann Grid Illusion
- Hermann-Hering Illusion
- Hermann-Mauguin Symbol
- Hermann's Formula
- Hermite Constants
- Hermite Differential Equation
- Hermite-Gauss Quadrature
- Hermite Interpolation
- Hermite-Lindemann Theorem
- Hermite Polynomial
- Hermite Quadrature
- Hermite's Interpolating Polynomial
- Hermite's Theorem
- Hermitian Form
- Hermitian Matrix
- Hermitian Operator