We compare the singular spectrum of a Banach algebra element with the usual spectrum and exponential spectrum.
@article{urn:eudml:doc:38571, title = {A note on the singular spectrum.}, journal = {Extracta Mathematicae}, volume = {13}, year = {1998}, pages = {349-357}, zbl = {1054.46510}, mrnumber = {MR1695568}, language = {en}, url = {http://dml.mathdoc.fr/item/urn:eudml:doc:38571} }
Lindeboom (Groenewald), L.; Raubenheimer, H. A note on the singular spectrum.. Extracta Mathematicae, Tome 13 (1998) pp. 349-357. http://gdmltest.u-ga.fr/item/urn:eudml:doc:38571/