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Operators of Hankel type. (English) Zbl 1164.47326

Summary: Considering Hankel operators and their symbols, as generalized by V.Pták and P.Vrbová [Acta Sci.Math.52, No.1/2, 117–140 (1988; Zbl 0661.47028)], the present note provides a parametric labeling of all the Hankel symbols of a given Hankel operator \(X\) by means of Schur class functions. The result includes uniqueness criteria and a Schur like formula. As a byproduct, a new proof of the existence of Hankel symbols is obtained. The proof is established by associating to the data of the problem a suitable isometry \(V\) so that there is a bijective correspondence between the symbols of \(X\) and the minimal unitary extensions of \(V\).

MSC:

47B35 Toeplitz operators, Hankel operators, Wiener-Hopf operators
47A20 Dilations, extensions, compressions of linear operators

Citations:

Zbl 0661.47028
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References:

[1] D. Z. Arov and L. Z. Grossman: Scattering matrices in the theory of extensions of isometric operators. Soviet Math. Dokl. 27 (1983), 518–522. · Zbl 0543.47010
[2] M. Cotlar and C. Sadosky: Prolongements des formes de Hankel gènèralisèes et formes de Toeplitz. C. R. Acad. Sci Paris Sér. I Math. 305 (1987), 167–170. · Zbl 0615.47007
[3] M. Cotlar and C. Sadosky: Integral representations of bounded Hankel forms defined in scattering systems with a multiparametric evolution group. Operator Theory: Adv. Appl. 35 (1988), 357–375. · Zbl 0679.47008
[4] A. Dijksma, S. A. M. Marcantognini and H. S. V. de Snoo: A Schur type analyisis of the minimal unitary Hilbert space extensions of a Kreĭn space isometry whose defect subspaces are Hilbert spaces. Z. Anal. Anwendungen 13 (1994), 233–260. · Zbl 0807.47012
[5] R. G. Douglas: On majorization, factorization, and range inclusion of operators on Hilbert space. Proc. Amer. Math. Soc. 17 (1966), 413–415. · Zbl 0146.12503 · doi:10.1090/S0002-9939-1966-0203464-1
[6] C. H. Mancera and P. J. Paúl: On Pták’s generalization of Hankel operators. Czechoslovak Math. J. 51 (2001), 323–342. · Zbl 0983.47019 · doi:10.1023/A:1013746930743
[7] C. H. Mancera and P. J. Paúl: Compact and finite rank operators satisfying a Hankel type equation T 2 X = XT 1 * . Integral Equations Operator Theory 39 (2001), 475–495. · Zbl 0980.47031 · doi:10.1007/BF01203325
[8] M. D. Morán: On intertwining dilations. J. Math. Anal. Appl. 141 (1989), 219–234. · Zbl 0693.47008 · doi:10.1016/0022-247X(89)90218-7
[9] V. Pták: Factorization of Toeplitz and Hankel operators. Math. Bohem. 122 (1997), 131–140. · Zbl 0892.47026
[10] V. Pták and P. Vrbová: Operators of Toeplitz and Hankel type. Acta Sci. Math. (Szeged) 52 (1988), 117–140. · Zbl 0661.47028
[11] V. Pták and P. Vrbová: Lifting intertwining relations. Integral Equations Operator Theory 11 (1988), 128–147. · Zbl 0639.47022 · doi:10.1007/BF01236657
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