Möbius Group
The equation
represents an
-D Hypersphere 
as a quadratic hypersurface in an 
-D real projective space
, where 
are homogeneous coordinates in . Then the Group 
of projectivetransformations which leave invariant is called the Möbius group.
References
Iyanaga, S. and Kawada, Y. (Eds.). ``Möbius Geometry.'' §78A in Encyclopedic Dictionary of Mathematics. Cambridge, MA: MIT Press, pp. 265-266, 1980.
- Descartes Folium
- Descartes' Formula
- Descartes Ovals
- Descartes' Sign Rule
- Descartes Total Angular Defect
- Descriptive Set Theory
- Design
- Design Theory
- de Sluze Conchoid
- de Sluze Pearls
- Desmic Surface
- Destructive Dilemma
- Determinant
- Determinant (Binary Quadratic Form)
- Determinant Expansion by Minors
- Determinant (Knot)
- Determinant Theorem
- Developable Surface
- Deviation
- Devil on Two Sticks
- Devil's Curve
- Devil's Staircase
- Diabolical Cube
- Diabolical Square
- Diabolo