Article
Keywords:
joint spectrum; Waelbroeck algebra; commutator; spectral mapping formula
Summary:
We give a necessary and a sufficient condition for a subset $S$ of a locally convex Waelbroeck algebra $\mathcal A$ to have a non-void left joint spectrum $\sigma _l(S).$ In particular, for a Lie subalgebra $L\subset \mathcal A$ we have $\sigma _l(L)\neq \emptyset $ if and only if $[L,L]$ generates in $\mathcal A$ a proper left ideal. \endgraf We also obtain a version of the spectral mapping formula for a modified left joint spectrum. Analogous theorems for the right joint spectrum and the Harte spectrum are also valid.
References:
[4] Nuñez, J. R.: A Joint Spectrum Associated to an Ideal. Tesis de Maestría, Universidad Autónoma Metropolitana, Ciudad de México (2017).
[6] Wawrzyńczyk, A.:
Joint spectra in Waelbroeck algebras. Bol. Soc. Mat. Mex., III. Ser. 13 (2007), 321-343.
MR 2472509 |
Zbl 1178.46047