Direct Product (Group)
The expression of a Group as a product of Subgroups. The Charactersof the representations of a direct product are equal to the products of the Characters of therepresentations based on the individual sets of functions. For 
and 
,
The representation of a direct product
will contain the totally symmetric representation only if theirreducible 
equals the irreducible 
.- Dandelin Spheres
- Danielson-Lanczos Lemma
- Darboux Integral
- Darboux-Stieltjes Integral
- Darboux Vector
- Darling's Products
- Dart
- Darwin-de Sitter Spheroid
- Darwin's Expansions
- Database
- Data Structure
- Daubechies Wavelet Filter
- Davenport-Schinzel Sequence
- Dawson's Integral
- Day of Week
- de Bruijn Constant
- de Bruijn Diagram
- de Bruijn Graph
- de Bruijn-Newman Constant
- de Bruijn Sequence
- de Bruijn's Theorem
- Debye Functions
- Debye's Asymptotic Representation
- Decagon
- Decagonal Number