Morse Theory
``Calculus of Variations in the large'' which uses nonlinear techniques to address problems in the Calculus ofVariations. Morse theory applied to a Function 
on a Manifold 
with 
and 
showsthat every Cobordism can be realized as a finite sequence of Surgeries. Conversely, a sequenceof Surgeries gives a Cobordism.
- Truncated Great Icosahedron
- Truncated Hexahedron
- Truncated Icosahedron
- Truncated Icosidodecahedron
- Truncated Octahedral Number
- Truncated Octahedron
- Truncated Polyhedron
- Truncated Pyramid
- Truncated Square Pyramid
- Truncated Tetrahedral Number
- Truncated Tetrahedron
- Truncation
- Truth Table
- Tschebyshev
- Tschirnhausen Cubic
- Tschirnhausen Cubic Caustic
- Tschirnhausen Cubic Pedal Curve
- Tschirnhausen Transformation
- Tubular Neighborhood
- Tucker Circles
- Tukey's Biweight
- Tukey's Trimean
- Tunnel Number
- Turbine
- Turing Machine