In this paper we discuss the range of a co-analytic Toeplitz operator. These range spaces are closely related to de Branges-Rovnyak spaces (in some cases they are equal as sets). In order to understand its structure, we explore when the range space decomposes into the range of an associated analytic Toeplitz operator and an identifiable orthogonal complement. For certain cases, we compute this orthogonal complement in terms of the kernel of a certain Toeplitz operator on the Hardy space, where we focus on when this kernel is a model space (backward shift invariant subspace). In the spirit of Ahern-Clark, we also discuss the non-tangential boundary behavior in these range spaces. These results give us further insight into the description of the range of a co-analytic Toeplitz operator as well as its orthogonal decomposition. Our Ahern-Clark type results, which are stated in a general abstract setting, will also have applications to related sub-Hardy Hilbert spaces of analytic functions such as the de Branges-Rovnyak spaces and the harmonically weighted Dirichlet spaces.
Copyright © 2018 Cambridge University Press. Article first published online: November 2018.
The definitive version is available at: https://www.cambridge.org/core/journals/canadian-journal-of-mathematics/article/range-spaces-of-coanalytic-toeplitz-operators/21E1EFED110090B3793D1EB2A5DA823D
Please note that downloads of the article are for private/personal use only.
Fricain, Emmanuel, Andrea Hartmann, and William T. Ross. "Range Spaces of Co-Analytic Toeplitz Operators." Canadian Journal of Mathematics-Journal Canadien De Mathematiques 70, no. 6 (December 2018): 1261-1283. https://doi.org/10.4153/CJM-2017-057-4
Fricain, Emmanuel; Hartmann, Andreas; and Ross, William T., "Range Spaces of Co-Analytic Toeplitz Operators" (2018). Math and Computer Science Faculty Publications. 222.