Orthonormal Basis
A Basis of Vectors 
which satisfy
or, in Tensor notation,
where
is the Kronecker Delta. An orthonormal basis is a normalized Orthogonal Basis.See also Basis, Orthogonal Basis- Perspective Center
- Perspective Collineation
- Perspective Triangles
- Perspectivity
- Pesin Theory
- Petersen Graphs
- Petersen-Shoute Theorem
- Peters Projection
- Peter-Weyl Theorem
- Petrie Polygon
- Petrov Notation
- Pfaffian Form
- p-Good Path
- p-Group
- Phase
- Phase Space
- Phase Transition
- Phasor
- Phi Curve
- Phi Number System
- Phragmén-Lindêlöf Theorem
- Phyllotaxis
- Pi
- Piano Mover's Problem
- Picard's Existence Theorem