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Pomona Faculty Publications and Research

Conjugation

Articles 1 - 4 of 4

Full-Text Articles in Mathematics

Unitary Equivalence To A Truncated Toeplitz Operator: Analytic Symbols, Stephan Ramon Garcia, Daniel E. Poore '11, William T. Ross Jan 2012

Unitary Equivalence To A Truncated Toeplitz Operator: Analytic Symbols, Stephan Ramon Garcia, Daniel E. Poore '11, William T. Ross

Pomona Faculty Publications and Research

Unlike Toeplitz operators on H², truncated Toeplitz operators do not have a natural matricial characterization. Consequently, these operators are difficult to study numerically. In this paper we provide criteria for a matrix with distinct eigenvalues to be unitarily equivalent to a truncated Toeplitz operator having an analytic symbol. This test is constructive, and we illustrate it with several examples. As a byproduct, we also prove that every complex symmetric operator on a Hilbert space of dimension ≤ 3 is unitarily equivalent to a direct sum of truncated Toeplitz operators.


The Norm Of A Truncated Toeplitz Operator, Stephan Ramon Garcia, William T. Ross Jan 2010

The Norm Of A Truncated Toeplitz Operator, Stephan Ramon Garcia, William T. Ross

Pomona Faculty Publications and Research

We prove several lower bounds for the norm of a truncated Toeplitz operator and obtain a curious relationship between the H2 and Hnorms of functions in model spaces.


Interpolation And Complex Symmetry, Stephan Ramon Garcia, Mihai Putinar Jan 2008

Interpolation And Complex Symmetry, Stephan Ramon Garcia, Mihai Putinar

Pomona Faculty Publications and Research

In a separable complex Hilbert space endowed with an isometric conjugate-linear involution, we study sequences orthonormal with respect to an associated bilinear form. Properties of such sequences are measured by a positive, possibly unbounded angle operator which is formally orthogonal as a matrix. Although developed in an abstract setting, this framework is relevant to a variety of eigenvector interpolation problems arising in function theory and in the study of differential operators.


Conjugation And Clark Operators, Stephan Ramon Garcia Jan 2006

Conjugation And Clark Operators, Stephan Ramon Garcia

Pomona Faculty Publications and Research

No abstract provided.