Title | Recent Progress in Operator Theory [electronic resource] : International Workshop on Operator Theory and Applications, IWOTA 95, in Regensburg, July 31-August 4,1995 / edited by I. Gohberg, R. Mennicken, C. Tretter |
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Imprint | Basel : Birkhรคuser Basel : Imprint: Birkhรคuser, 1998 |
Connect to | http://dx.doi.org/10.1007/978-3-0348-8793-9 |
Descript | XIII, 288 p. online resource |
Inversion formulas for compressions of block-Toeplitz operators -- 1. Introduction -- 2. Main results -- 3. Inversion formulas for block-Toeplitz and block-Pick matrices -- 4. Inversion formulas for block-Toeplitz integral operators in 5-1 (0, a) (a < ?) -- References -- Contractive linear relations in Pontryagin spaces -- 1. Introduction -- 2. Contractive linear relations -- 3. Regularization -- 4. Criteria for maximality -- 5. Properties of maximal contractive linear relations -- 6. Invariant subspaces -- References -- On a new algorithm for almost periodic factorization -- 1. Introduction -- 2. Known results -- 3. The reduction procedure -- 4. Matrices with regular Fourier spectra -- 5. Repeated use of the reduction procedure -- 6. Trinomial f -- 7. Block matrix generalizations -- 8. Final remarks -- References -- On the normal solvability of cohomological equations on compact topological spaces -- 1. Introduction -- 2. Dynamical lemmas -- 3. Proof of the Main Theorem -- 4. Appendix -- References -- On nonnegative realizations of rational matrix functions and nonnegative input-output systems -- 1. Introduction -- 2. Nonnegative realizations of rational matrix functions -- 3. Nonnegative input output systems -- 4. Appendix -- References -- On the geometric structure of regular dilations -- 1. Notations and preliminaries -- 2. The structure of regular and *-regular isometric dilations -- 3. Functional model and maximal function for a bicontraction having a *-regular dilation -- References -- On generalized interpolation and shift invariant maximal semidefinite subspaces -- 1. Introduction -- 2. Preliminaries -- 3. Generalized interpolation -- 4. The bitangential Nevanlinna-Pick problem -- References -- The sum of matrix Nevanlinna functions and self-adjoint extensions in exit spaces -- 1. Introduction -- 2. Nevanlinna pairs -- 3. Kre 6-1 nโs formula -- 4. The sum of Q-functions -- 5. The orthogonal sum of Sturm-Liouville operators -- 6. Schur complements of Q-functions -- 7. Nevanlinna functions and exit spaces -- References -- Properties of โderivedโ Hankel matrices -- 1. Introduction -- 2. Representations of m-derived Hankel matrices -- 3. Vandermonde factorization -- 4. Generating functions and Bezoutians -- 5. Triangular derived Hankel matrices -- References -- The probability that a (partial) matrix is positive semidefinite -- 1. Introduction -- 2. The case of full matrices -- 3. The case of partial matrices -- 4. The probability of the existence of a positive semidefinite completion -- References -- Factorization of lower triangular unitary operators with finite Kronecker index into elementary factors -- 1. Introduction -- 2. Unitary time varying systems -- 3. Observability and controllability of unitary time varying systems -- 4. A realization theorem -- 5. Cascade connection and factorization -- 6. Proof of Theorems 1.1 and 1.2 -- 7. Main theorems for operators in the class LK -- References -- Fredholm theory of interpolation morphisms -- 1. Introduction -- 2. Fredholm theory in a paraalgebra of interpolation morphisms -- 3. Interpolation of Fredholm elements -- 4. Perturbation results for the real interpolation methods -- References -- Resolvents of symmetric operators and the degenerated Nevanlinna-Pick problem -- 1. Introduction -- 2. Straus extensions -- 3. The u-resolvents of S -- 4. The degenerated Nevanlinna-Pick problem -- 5. Explicit formulas -- References -- Perturbation of linear semigroups -- 1. Introduction -- 2. Essential spectral radius for perturbed semigroups -- References -- On the approximation of operators and the convergence of the spectra of the approximants -- 1. Introduction -- 2. The main result -- 3. Auxiliary results and proofs -- References