Group Orthogonality Theorem
Let 
be a representation for a Group of Order 
,then
The proof is nontrivial and may be found in Eyring et al. (1944).
References
Eyring, H.; Walker, J.; and Kimball, G. E. Quantum Chemistry. New York: Wiley, p. 371, 1944.
- Sinusoidal Spiral
- Sinusoidal Spiral Inverse Curve
- Sinusoidal Spiral Pedal Curve
- Sister Celine's Method
- Site Percolation
- Siteswap
- Six-Color Theorem
- Skein Relationship
- Skeleton
- Skeleton Division
- Skew Conic
- Skewes Number
- Skew Field
- Skew Lines
- Skewness
- Skew Polyomino
- Skew Quadrilateral
- Skew Symmetric Matrix
- Sklar's Theorem
- Skolem-Mahler-Lerch Theorem
- Skolem Paradox
- Skolem Sequence
- Slant Height
- Slice Knot
- Slide Move