# Start a new discussion

## Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

## Discussion Tag Cloud

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

• CommentRowNumber1.
• CommentAuthorUrs
• CommentTimeOct 18th 2017
• (edited Oct 18th 2017)

added statement and proof that compactly supported distributions are equivalently the smooth linear functionals: here

(in the sense of either diffeological spaces, or smooth sets, or formal smooth sets/Cahiers topos).

• CommentRowNumber2.
• CommentAuthorUrs
• CommentTimeOct 23rd 2017
• (edited Oct 23rd 2017)

I have spelled out here the characterization of continuity of a linear map $u \colon C^\infty(\mathbb{R}^n) \to \mathbb{R}$ as in Hörmander’s book

$\underset{K,k,C}{\exists} \left( \vert u(\Phi) \vert \;\leq\; C \underset{ {\vert \alpha \vert \leq k} }{\sum} \underset{x \in K}{sup} \vert \partial^\alpha K \vert \right)$

from the un-summed seminorms $\Phi \mapsto \underset{x \in K}{sup} {\vert \partial^\alpha \Phi(x) \vert}$.