Abstract
Bitangential interpolation problems in the class of matrix valued functions in the generalized Schur class are considered in both the open unit disc and the open right half plane, including problems in which the solutions is not assumed to be holomorphic at the interpolation points. Linear fractional representations of the set of solutions to these problems are presented for invertible and singular Hermitian Pick matrices. These representations make use of a description of the ranges of linear fractional transformations with suitably chosen domains that was developed in Derkach and Dym (On linear fractional transformations associated with generalized J-inner matrix functions. Integ Eq Oper Th (2009, in press) arXiv:0901.0193).
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Alpay D., Bolotnikov V., Dijksma A.: On the Nevanlinna-Pick interpolation problem for generalized Stieltjes functions. Integr. Equ. Oper. Theory 30(4), 379–408 (1998)
Alpay D., Constantinescu T., Dijksma A., Rovnyak J.: Notes on interpolation in the generalized Schur class. II, Nudel’man’s problem. Trans. Am. Math. Soc. 355(2), 813–836 (2003)
Alpay, D., Dijksma, A., Rovnyak, J., de Snoo, H.S.V.: Schur functions, operator colligations, and reproducing kernel Pontryagin spaces. Oper. Theory: Adv. Appl., vol. 96. Birkhäuser Verlag, Basel (1997)
Alpay, D., Dym, H.: On applications of reproducing kernel spaces to the Schur algorithm and rational J unitary factorization. I. Schur methods in operator theory and signal processing. Oper. Theory Adv. Appl., vol. 18, pp. 89–159. Birkhäuser, Basel (1986)
Alpay D., Dym H.: On a new class of realization formulas and their application. Linear Algebra Appl. 241/243, 3–84 (1996)
Amirshadyan A., Derkach V.: Interpolation in generalized Nevanlinna and Stieltjes classes. J. Oper. Theory 42, 145–188 (1999)
Aronszajn N.: Theory of reproducing kernels. Trans. Am. Math. Soc. 68, 337–404 (1950)
Arov D.Z.: The generalized bitangent Caratheodory-Nevanlinna-Pick problem, and (j, J 0)-inner matrix valued functions. Russian Acad. Sci. Izv. Math. 42(1), 1–26 (1994)
Arov D.Z., Dym H.: J-inner matrix functions, interpolation and inverse problems for canonical systems. Integr. Equ. Oper. Theory 29, 373–454 (1997)
Arov D.Z., Dym H.: J-contractive matrix valued functions and related topics. Encyclopedia of Mathematics and its Applications, vol. 116. Cambridge University Press, Cambridge (2008)
Azizov, T.Ya., Iokhvidov, I.S.: Foundations of the Theory of Linear Operators in Spaces with an Indefinite Metric. Nauka, Moscow (1986) (English translation: Wiley, New York, 1989)
Ball J.A., Helton J.W.: A Beurling–Lax theorem for the Lie group U(m, n) which contains most classical interpolation theory. J. Oper. Theory 9, 107–142 (1983)
Ball J.A., Helton J.W.: Interpolation problems of Pick–Nevanlinna and Loewner types for meromorphic matrix functions. Integr. Equ. Oper. Th. 9, 155–203 (1986)
Ball J.A., Gohberg I., Rodman L.: Interpolation of Rational Matrix Functions, vol. OT45. Birkhäuser Verlag, Basel (1990)
Bognar J.: Indefinite inner product spaces. Ergeb. Math. Grenzgeb., Bd., vol. 78. Springer, New York- Heidelberg (1974)
Bolotnikov V.: On Caratheodory-Fejer problem for generalized Schur functions. Integr. Equ. Oper. Theory 50, 9–41 (2004)
Bolotnikov V., Dym H.: On degenerate interpolation, entropy and extremal problems for matrix Schur functions. Integr. Equ. Oper. Theory 32(4), 367–435 (1998)
de Branges, L., Rovnyak, J.: Canonical models in quantum scattering theory. In: Perturbation Theory and its Application in Quantum Mechanics, pp. 359–391. Wiley, New York (1966)
Derkach V.: On indefinite abstract interpolation problem. Methods Funct. Anal. Topol. 7(4), 87–100 (2001)
Derkach V.: On Schur-Nevanlinna-Pick indefinite interpolation problem. Ukrainian Math. Zh. 55(10), 1567–1587 (2003)
Derkach, V., Dym, H.: On linear fractional transformations associated with generalized J–inner matrix functions. Integ. Equ. Oper. Theory (2009, in press), arXiv:0901.0193
Dijksma, A., Langer, H.: Notes on a Nevanlinna–Pick interpolation problem for generalized Nevanlinna functions. Oper. Theory: Adv. Appl., vol. 95, pp. 69–91. Birkhäuser Verlag, Basel (1997)
Duren P.L.: Theory of H p Spaces. Academic Press, New York (1970)
Dym, H.: J–contractive matrix functions, reproducing kernel Hilbert spaces and interpolation. CBMS Regional Series in Math., vol. 71. Providence, RI (1989)
Dym, H.: A basic interpolation problem. Holomorphic spaces (Berkeley, CA, 1995). Math. Sci. Res. Inst. Publ., vol. 33, pp. 381–423. Cambridge Univ. Press, Cambridge (1998)
Dym, H.: On Riccati equations and reproducing kernel spaces. In: Recent Advances in Operator Theory. Oper. Theory: Adv. Appl., vol. OT124, pp. 189–215. Birkhäuser, Basel (2001)
Dym, H.: Riccati equations and bitangential interpolation problems with singular Pick matrices. Fast algorithms for structured matrices: theory and applications (South Hadley, MA 2001). Contemp. Math., vol. 323, pp. 361–391. Amer. Math. Soc., Providence (2003)
Dym, H.: Linear fractional transformations, Riccati equations and bitangential interpolation, revisited. Reproducing kernel spaces and applications. Oper. Theory: Adv. Appl., vol. 143, pp. 171–212. Birkhäuser, Basel (2003)
Dym H.: Linear Algebra in Action. Amer. Math. Soc., Providence (2007)
Gohberg I.C., Sigal E.I.: An operator generalization of the logarithmic residue theorem and the theorem of Rouche. Math. Sbornik 84, 607–629 (1971)
Golinskii L.B.: On a generalization of matrix Nevalinna- Pick problem. Izvestija Arm. Acad Nauk 18(3), 187–205 (1983)
Fuhrmann P.A.: On the corona theorem and its application to spectral problems in Hilbert space. Trans. AMS 132, 55–66 (1968)
Katsnelson, V.E., Kheifets, A.Ya., Yuditskii, P.M.: The abstract interpolation problem and extension theory of isometric operators. In: Operators in Spaces of Functions and Problems in Function Theory, pp. 83–96. Kiev, Naukova Dumka (1987) (Russian)
Kimura H.: Chain Scattering Approach to H ∞ Control. Birkhäuser, Boston (1997)
Kheifets, A.Ya., Yuditskii, P.M.: An analysis and extension of V. P. Potapov’s approach to intrpolation problems with applications to the generalized bi-tangential Schur-Nevanlinna- Pick problem and J-inner-outer factorization. Oper. Theory: Adv. Appl., vol. 72, pp. 133–161. Birkhäuser, Basel (1994)
Kreĭn, M.G., Langer, H.: Über die verallgemeinerten Resolventen und die characteristische Function eines isometrischen Operators im Raume Π κ , Hilbert space Operators and Operator Algebras (Proc. Intern. Conf., Tihany, 1970); Colloq. Math. Soc. Janos Bolyai, vol. 5, pp. 353–399. North–Holland, Amsterdam (1972)
Kreĭn M.G., Langer H.: Über die Q–functions eines π–hermiteschen Operators im Raume Π κ . Acta Sci. Math. (Szeged) 34, 191–230 (1973)
Kreĭn M.G., Langer H.: Some propositions of analytic matrix functions related to the theory of operators in the space Π κ . Acta Sci. Math. Szeged 43, 181–205 (1981)
Nudelman A.A.: On a generalization of classical intrepolation problems. Dokl. Akad. Nauk SSSR 256, 790–793 (1981)
Potapov V.P.: Multiplicative structure of J-nonexpanding matrix functions. Trudy Mosk. Matem. Obsch. 4, 125–236 (1955)
Schwartz L.: Sous espaces hilbertiens d’espaces vectoriels topologiques et noyaux associes. J. Anal. Math. 13, 115–256 (1964)
Takagi T.: On an algebraic problem related to an analytic theorem of Carathéodory and Fejér. Jpn. J. Math. 1, 83–93 (1924)
Woracek H.: Nevanlinna-Pick interpolation: the degenerated case. Linear Algebra Appl. 252, 141–158 (1997)
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Communicated by Daniel Alpay.
V. Derkach wishes to thank the Weizmann Institute of Science for hospitality and support.
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Derkach, V., Dym, H. Bitangential Interpolation in Generalized Schur Classes. Complex Anal. Oper. Theory 4, 701–765 (2010). https://doi.org/10.1007/s11785-009-0031-3
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DOI: https://doi.org/10.1007/s11785-009-0031-3
Keywords
- Bitangential interpolation
- Generalized Schur class
- Kreĭn–Langer factorization
- Resolvent matrix
- Linear fractional transformation
- Coprime factorization