We consider the reducibility and unitary equivalence of multiplication operators on the Dirichlet space. We first characterize reducibility of a multiplication operator induced by a finite Blaschke product and, as an application, we show that a multiplication operator induced by a Blaschke product with two zeros is reducible only in an obvious case. Also, we prove that a multiplication operator induced by a multiplier ϕ is unitarily equivalent to a weighted shift of multiplicity 2 if and only if ϕ = λz² for some unimodular constant λ.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-sm220-2-3, author = {Yong Chen and Young Joo Lee and Tao Yu}, title = {Reducibility and unitary equivalence for a class of multiplication operators on the Dirichlet space}, journal = {Studia Mathematica}, volume = {223}, year = {2014}, pages = {141-156}, zbl = {1298.47047}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm220-2-3} }
Yong Chen; Young Joo Lee; Tao Yu. Reducibility and unitary equivalence for a class of multiplication operators on the Dirichlet space. Studia Mathematica, Tome 223 (2014) pp. 141-156. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm220-2-3/