The Commutant Lifting Approach to Interpolation Problems: v. 44 - Rilegato

Foias, Ciprian; Frazho, A. E.

Rilegato

ISBN 10: 3764324619 ISBN 13: 9783764324612

Casa editrice: Birkhauser Verlag AG, 1990

Riassunto

Classical H~ interpolation theory was conceived at the beginning of the century by C. Caratheodory, L. Fejer and I. Schur. The basic method, due to Schur, in solving these problems consists in applying the Mobius transform to peel off the data. In 1967, D. Sarason encompassed these classical interpolation problems in a representation theorem of operators commuting with special contractions. Shortly after that, in 1968, B. Sz.- Nagy and C. Foias obtained a purely geometrical extension of Sarason's results. Actually, their result states that operators intertwining restrictions of co-isometries can be extended, by preserving their norm, to operators intertwining these co-isometries; starring with R. G. Douglas, P. S. Muhly and C. Pearcy, this is referred to as the commutant lifting theorem. In 1957, Z. Nehari considered an L ~ interpolation problern which in turn encompassed the same classical interpolation problems, as well as the computation of the distance of a function f in L ~ to H~. At about the sametime as Sarason's work, V. M.

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Contenuti

I. Analysis of the Caratheodory Interpolation Problem.- II. Analysis of the Caratheodory Interpolation Problem for Positive-Real Functions.- III. Schur Numbers, Geophysics and Inverse Scattering Problems.- IV. Contractive Expansions on Euclidian and Hilbert Space.- V. Contractive One Step Intertwining Liftings.- VI. Isometric and Unitary Dilations.- VII. The Commutant Lifting Theorem.- VIII. Geometric Applications of the Commutant lifting Theorem.- IX. H? Optimization and Functional Models.- X. Some Classical Interpolation Problems.- XI. Interpolation as a Momentum Problem.- XII. Numerical Algorithms for H? Optimization in Control Theory.- XIII. Inverse Scattering Algorithms for the Commutant Lifting Theorem.- XIV. The Schur Representation.- XV. A Geometric Approach to Positive Definite Sequences.- XVI. Positive Definite Block Matrices.- XVII. A Physical Basis for the Layered Medium Model.- References.- Notation.

Dettagli dell?edizione

• Editore: Birkhauser Verlag AG
• Data di pubblicazione: 1990
• Lingua: Inglese
• ISBN 10: 3764324619
• ISBN 13: 9783764324612
• Rilegatura: Copertina rigida
• Numero edizione: 1
• Numero di pagine: 632
• Contatto del produttore: non disponibile
• Persona responsabile: non disponibile