Double dual

{{ safesubst: #invoke:RfD|||month = July
 * day = 14
 * year = 2024
 * time = 18:21
 * timestamp = 20240714182117


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 * 1) REDIRECT Dual space

In mathematics, any vector space V has a corresponding double dual vector space (or just double dual for short) defined as the dual space of the dual space of V.

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In mathematics, the double dual is the dual of the dual of an object, for various definitions of duality. Examples include:


 * Algebraic vector space, $$V^{**}$$: {{slink|Dual space|Injection into the double-dual}}
 * Topological vector space, $V''$: {{slink|Dual space|Double dual}}
 * Normed vector space, $$V^{**}$$: {{slink|Dual norm|The double dual of a normed linear space}}
 * Locally compact abelian group, $$\widehat{\widehat{G}}$$: Pontryagin duality
 * Module, $$M^{**}$$: Dual module