We present a new approach to the question of when the commutativity of operator exponentials implies that of the operators. This is proved in the setting of bounded normal operators on a complex Hilbert space. The proofs are based on some results on similarities by Berberian and Embry as well as the celebrated Fuglede theorem.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm125-1-1, author = {Mohammed Hichem Mortad}, title = {Exponentials of normal operators and commutativity of operators: a new approach}, journal = {Colloquium Mathematicae}, volume = {122}, year = {2011}, pages = {1-6}, zbl = {1259.47002}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm125-1-1} }
Mohammed Hichem Mortad. Exponentials of normal operators and commutativity of operators: a new approach. Colloquium Mathematicae, Tome 122 (2011) pp. 1-6. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm125-1-1/