Let B be a complex topological unital algebra. The left joint spectrum of a set S ⊂ B is defined by the formula = generates a proper left idealUsing the Schur lemma and the Gelfand-Mazur theorem we prove that has the spectral mapping property for sets S of pairwise commuting elements if (i) B is an m-convex algebra with all maximal left ideals closed, or (ii) B is a locally convex Waelbroeck algebra. The right ideal version of this result is also valid.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-ba55-1-7, author = {Antoni Wawrzy\'nczyk}, title = {Schur Lemma and the Spectral Mapping Formula}, journal = {Bulletin of the Polish Academy of Sciences. Mathematics}, volume = {55}, year = {2007}, pages = {63-69}, zbl = {1118.46045}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-ba55-1-7} }
Antoni Wawrzyńczyk. Schur Lemma and the Spectral Mapping Formula. Bulletin of the Polish Academy of Sciences. Mathematics, Tome 55 (2007) pp. 63-69. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-ba55-1-7/