Editing Dyadic rational (section)

===Dyadic solenoid===
Considering only the addition and subtraction operations of the dyadic rationals gives them the structure of an additive [[abelian group]]. [[Pontryagin duality]] is a method for understanding abelian groups by constructing dual groups, whose elements are [[Character (mathematics)|characters]] of the original group, [[group homomorphism]]s to the multiplicative group of the [[complex number]]s, with pointwise multiplication as the dual group operation. The dual group of the additive dyadic rationals, constructed in this way, can also be viewed as a [[topological group]]. It is called the dyadic solenoid, and is isomorphic to the topological product of the real numbers and 2-adic numbers, [[Quotient group|quotiented]] by the [[Diagonal morphism|diagonal embedding]] of the dyadic rationals into this product.{{r|manners}} It is an example of a [[protorus]], a [[Solenoid (mathematics)|solenoid]], and an [[indecomposable continuum]].{{r|nadler}}