Document Type
Article - preprint
Department
Mathematics (Pomona)
Publication Date
2009
Keywords
truncated Toeplitz Operators, spatial isomorphism, unitary equivalence
Abstract
A truncated Toeplitz operator A φ : K Θ → K Θ is the compression of a Toeplitz operator T φ : H 2 → H 2 to a model space K Θ ≔ H 2 ⊖ Θ H 2 . For Θ inner, let T Θ denote the set of all bounded truncated Toeplitz operators on K Θ . Our main result is a necessary and sufficient condition on inner functions Θ 1 and Θ 2 which guarantees that T Θ 1 and T Θ 2 are spatially isomorphic (i.e., U T Θ 1 = T Θ 2 U for some unitary U : K Θ 1 → K Θ 2 ). We also study operators which are unitarily equivalent to truncated Toeplitz operators and we prove that every operator on a finite dimensional Hilbert space is similar to a truncated Toeplitz operator.
Rights Information
© 2010 Indiana University Mathematics Journal
Terms of Use & License Information
Recommended Citation
Cima, Joseph A.; Garcia, Stephan Ramon; Ross, William T.; and Wogen, Warren R., "Truncated Toeplitz Operators: Spatial Isomorphism, Unitary Equivalence, and Similarity" (2009). Pomona Faculty Publications and Research. 247.
https://scholarship.claremont.edu/pomona_fac_pub/247
Comments
Pre-print from http://arxiv.org/abs/0907.2489
Final publication can be found at:
Cima, J.A., Garcia, S.R., Ross, W.T., Wogen, W.R., Truncated Toeplitz operators: spatial isomorphism, unitary equivalence, and similarity, Indiana Univ. Math. J., 59 (2010), 595–620. MR2648079 (2011i:47035). http://www.iumj.indiana.edu/oai/2010/59/4097/4097.xml