Stiefel-Whitney Class

The th Stiefel-Whitney class of a Real Vector Bundle (or Tangent Bundle or aReal Manifold) is in the th cohomology group of the base Space involved. It is anObstruction to the existence of Real linearly independent VectorFields on that Vector Bundle, where is the dimension of the Fiber. Here,Obstruction means that the th Stiefel-Whitney class being Nonzero implies that there do notexist everywhere linearly dependent Vector Fields (although theStiefel-Whitney classes are not always the Obstruction).

In particular, the th Stiefel-Whitney class is the obstruction to the existence of an everywhere NonzeroVector Field, and the first Stiefel-Whitney class of a Manifold is the obstruction to orientability.

• Prime Ring
• Prime Sequence
• Prime Spiral
• Prime String
• Prime Sum
• Prime Theta Function
• Prime Triangle
• Prime Unit
• Prime Zeta Function
• Primitive Abundant Number
• Primitive Function
• Primitive Irreducible Polynomial
• Primitive Polynomial Modulo 2
• Primitive Prime Factor
• Primitive Pseudoperfect Number
• Primitive Recursive Function
• Primitive Root
• Primitive Root of Unity
• Primitive Semiperfect Number
• Primitive Sequence
• Primorial
• Prince Rupert's Cube
• Principal
• Principal Curvatures
• Principal Curve