Category:Unitizations of Normed Algebras

From ProofWiki
Jump to navigation Jump to search

This category contains results about Unitizations of Normed Algebras.
Definitions specific to this category can be found in Definitions/Unitizations of Normed Algebras.

Let $\GF \in \set {\R, \C}$.

Let $\struct {A, \norm {\, \cdot \,} }$ be a normed algebra over $\GF$ that is not unital as an algebra.

Let $A_+$ be the unitization of $A$.

Define $\norm {\, \cdot \,}_{A_+} : A_+ \to \hointr 0 \infty$ by:

$\norm {\tuple {x, \lambda} }_{A_+} = \norm x + \cmod \lambda$

for each $\tuple {x, \lambda} \in A_+$.


We call $\struct {A_+, \norm {\, \cdot \,}_{A_+} }$ the unitization of $\struct {A, \norm {\, \cdot \,} }$.