Category:Spectra (Unital Algebras)

This category contains results about Spectra (Unital Algebras).
Definitions specific to this category can be found in Definitions/Spectra (Unital Algebras).

Let $A$ be a unital algebra over $\C$.

Let $x \in A$.

Let $\map {\rho_A} x$ be the resolvent set of $x$ in $A$.

We define and denote the spectrum of $x$ by:

$\map {\sigma_A} x := \C \setminus \map {\rho_A} x$