User:Fropuff/Spheres

The articles on spheres need some reworking/reorganization. Here is what I propose.

Main articles

• sphere (with redirects from 2-sphere, and unit sphere) - This article should concentrate on the ordinary 2-dimensional sphere in Euclidean 3-space.
• n-sphere (with a redirect from hypersphere) - This article should treat the general case with sections on geometry and topology.

Specific spheres

• 0-sphere
• 1-sphere → circle
  • unit circle
  • circle group
• 2-sphere → sphere
  • Riemann sphere
• 3-sphere
  • 3-sphere group
• 4-sphere
• 5-sphere
• 6-sphere
• 7-sphere
• 8-sphere

Algebraic structure

• circle group (with redirects from U(1), SO(2) and Spin(2))
• 3-sphere group (with redirects from SU(2), Sp(1), Spin(3), and unit quaternion group)

Topology of spheres

• Homology sphere
  • Poincaré sphere
• Homotopy sphere
• Homotopy groups of spheres
• Alexander horned sphere
• Exotic sphere