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Canonical Transfer-function Realization for Schur-Agler-class Functions of the Polydisk

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A Panorama of Modern Operator Theory and Related Topics

Part of the book series: Operator Theory: Advances and Applications ((OT,volume 218))

Abstract

Associated with any Schur-class function S((z)) (i.e., a contractive operator-valued holomorphic function on the unit disk) is the de Branges- Rovnyak kernel Ks((z,C)) = [=([I-S(z))S(C)) * ]/(1) and the reproducing kernel Hilbert space H(KS) which serves as the canonical functional-model statespace for a coisometric transfer-function realization s((z)) = D+z(A)1B of S. To obtain a canonical functional-model unitary transfer-function realization, it is now well understood that one must work with a certain (2 × 2)- block matrix kernel and associated two-component reproducing kernel Hilbert space. In this paper we indicate how these ideas extend to the multivariable setting where the unit disk is replaced by the unit polydisk in d complex variables. For the case d> 2, one must replace the Schur class by the more restrictive Schur-Agler class (defined in terms of the validity of a certain von Neumann inequality) in order to get a good realization theory paralleling the single-variable case. This work represents one contribution to the recent extension of the state-space method to multivariable settings, an area of research where Israel Gohberg was a prominent and leading practitioner.

Mathematics Subject Classification (2000). 47A57.

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References

  1. V.M. Adamjan and D.Z. Arov, On unitary coupling of semi-unitary operators, Dokl. Akad. Nauk. Arm. SSR 43 (1966), no. 5, 257–263.

    MathSciNet  Google Scholar 

  2. J. Agler. On the representation of certain holomorphic functions defined on a polydisk, in Topics in Operator Theory: Ernst D. Hellinger memorial Volume (eds. L. de Branges, I. Gohberg and J. Rovnyak), Oper. Theory Adv. Appl. OT 48, pp. 47–66, Birkhäuser Verlag, Basel, 1990.

    Google Scholar 

  3. J. Agler and J.E. McCarthy, Nevanlinna-Pick interpolation on the bidisk, J. Reine Angew. Math. 506 (1999), 191–204.

    Article  MathSciNet  MATH  Google Scholar 

  4. J. Agler and J.E. McCarthy, Complete Nevanlinna-Pick kernels, J. Funct. Anal. 175 (2000) no. 1, 111–124.

    Article  MathSciNet  MATH  Google Scholar 

  5. D. Alpay and C. Dubi, Backward shift operator and finite-dimensional de Branges-Rovnyak spaces in the ball, Linear Algebra Appl. 371 (2003), 277–285.

    Article  MathSciNet  MATH  Google Scholar 

  6. D. Alpay and C. Dubi, A realization theorem for rational functions of several complexvariables, Systems Control Lett. 49 (2003) no. 3, 225–229.

    Article  MathSciNet  MATH  Google Scholar 

  7. D. Alpay, A. Dijksma, J. Rovnyak, and H. de Snoo, Schur functions, operator colligations,and reproducing kernel Pontryagin spaces, Oper. Theory Adv. Appl. OT 96, Birkhäuser Verlag, Basel, 1997.

    Google Scholar 

  8. D. Alpay and D.S. Kalyuzhnyi-Verbovetzkyi, Matrix-J-unitary non-commutative rational formal power series, in The State Space Method: Generalizations and Applications pp. 49–113 (eds. D. Alpay and I. Gohberg), Oper. Theory Adv. Appl. OT 161, Birkhäuser Verlag, Basel-Boston-Berlin, 2006.

    Google Scholar 

  9. D. Alpay and H.T. Kaptanoğlu, Gleason’s problem and homogeneous interpolation in Hardy and Dirichlet-type spaces of the ball, J. Math. Anal. Appl. 276 (2002) no. 2, 654–672.

    Google Scholar 

  10. C.-G. Ambrozie and D. Timotin, A von Neumann type inequality for certain domains inn, Proc. Amer. Math. Soc., 131 (2003), no. 3, 859–869.

    Article  MathSciNet  MATH  Google Scholar 

  11. N. Aronszajn, Theory of reproducing kernels, Trans. Amer. Math. Soc., 68 (1950), 337–404.

    Article  MathSciNet  MATH  Google Scholar 

  12. D.Z. Arov and O.J. Staffans, A Kreĭn-space coordinate-free version of the de Branges-Rovnyak complementary space, J. Funct. Anal. 256 (2009) no. 12, 3892–3915.

    Article  MathSciNet  MATH  Google Scholar 

  13. D.Z. Arov and O.J. Staffans, Two canonical passive state/signal shift realizations of passive discrete-time behaviors, J. Funct. Anal. 257 (2009) no. 8, 2573–2634.

    Article  MathSciNet  MATH  Google Scholar 

  14. J.A. Ball, Linear systems, operator model theory and scattering: multivariable generalizations, in: Operator theory and its applications, 151–178, Fields Inst. Commun., 25, Amer. Math. Soc., Providence, RI, 2000.

    Google Scholar 

  15. J.A. Ball, A. Biswas, Q. Fang and S. ter Horst, Multivariable generalizations of the Schur class: positive kernel characterization and transfer function realization, in Recent advances in operator theory and applications (eds. T. Ando, R.E. Curto, I.B. Jung, and W.Y. Lee), pp. 17–79, Oper. Theory Adv. Appl. OT 187, Birkhäuser Verlag, 2009.

    Google Scholar 

  16. J.A. Ball and V. Bolotnikov, Realization and interpolation for Schur-Agler-class functions on domains with matrix polynomial defining function inn, J. Funct. Anal. 213 (2004), no.1, 45–87.

    Article  MathSciNet  MATH  Google Scholar 

  17. J.A. Ball and V. Bolotnikov, Canonical de Branges-Rovnyak model transfer-function realization for multivariable Schur-class functions, in Hilbert Spaces of Analytic Functions (eds. J. Mashreghi, T. Ransford, and K. Seip), CRM Proceedings & Lecture Notes 51, Amer. Math. Soc., Providence, 2010.

    Google Scholar 

  18. J.A. Ball and V. Bolotnikov, Canonical transfer-function realization for Schur-Aglerclass functions on domains with matrix polynomial defining functions inn, in Recent Progress in Operator Theory and Its Applications, J.A. Ball, R. Curto, S. Grudsky, J.W. Helton, R. Quiroga-Barrancoi, and N. Vasilevski, eds., Proceedings of the International Workshop on Operator Theory and Applications (IWOTA), Guanajuato, Mexico, Oper. Theory Adv. Appl. OT 220, Birkhäuser, Springer Basel AG, 2012, 23–55.

    Google Scholar 

  19. J.A. Ball and V. Bolotnikov, Canonical transfer-function realization for Schur multipliers on the Drury-Arveson space and models for commuting row contractions, Ind. U. Math. J., to appear.

    Google Scholar 

  20. J.A. Ball, V. Bolotnikov and Q. Fang, Transfer-function realization for multipliers of the Arveson space, J. Math. Anal. Appl. 333 (2007), no. 1, 68–92.

    Article  MathSciNet  MATH  Google Scholar 

  21. J.A. Ball, V. Bolotnikov and Q. Fang, Schur-class multipliers on the Fock space: de Branges-Rovnyak reproducing kernel spaces and transfer-function realizations, in Operator Theory, Structured Matrices, and Dilations: Tiberiu Constantinescu Memorial Volume (eds. M. Bakonyi, A. Gheondea, M. Putinar and J. Rovnyak), pp. 85–114, Theta Press, Bucharest, 2007.

    Google Scholar 

  22. J.A. Ball, K.F. Clancey, and V. Vinnikov, Concrete interpolation of meromorphic matrix functions on Riemann surfaces, in Reproducing kernel spaces and applications pp. 77–134, Oper. Theory Adv. Appl. OT 143, Birkhäuser Verlag, 2003.

    Google Scholar 

  23. J.A. Ball, I. Gohberg, and L. Rodman, Interpolation of rational matrix functions, Oper. Theory Adv. Appl. OT 45, Birkhäuser Verlag, Basel, 1990.

    Google Scholar 

  24. J.A. Ball, G. Groenewald and T. Malakorn, Structured noncommutative multidimensional linear systems, SIAM J. Control Optim. 44 (2005), no. 4, 1474–1528.

    Article  MathSciNet  MATH  Google Scholar 

  25. J.A. Ball, G. Groenewald and T. Malakorn, Conservative structured noncommutative multidimensional linear systems, in The State Space Method: Generalizations and Applications (eds. D. Alpay and I. Gohberg), pp. 179–223, Oper. Theory Adv. Appl. OT 161, Birkhäuser Verlag, Basel, 2006.

    Google Scholar 

  26. J.A. Ball, D.S. Kaliuzhnyi-Verbovetskyi, C. Sadosky, V. Vinnikov, Scattering systems with several evolutions and formal reproducing kernel Hilbert spaces, in preparation.

    Google Scholar 

  27. J.A. Ball, C. Sadosky, V. Vinnikov, Scattering systems with several evolutions and multidimensional input/.state/output systems, Integral Equations Operator Theory 52 (2005), no. 3, 323–393.

    Google Scholar 

  28. J.A. Ball and T.T. Trent, Unitary colligations, reproducing kernel Hilbert spaces and Nevanlinna–Pick interpolation in several variables, J. Funct. Anal., 157 (1998), no. 1, 1–61.

    Article  MathSciNet  MATH  Google Scholar 

  29. J.A. Ball, T.T. Trent and V. Vinnikov, Interpolation and commutant lifting for multipliers on reproducing kernel Hilbert spaces, in Operator Theory and Analysis: The M.A. Kaashoek Anniversary Volume (eds. H. Bart, I. Gohberg and A.C.M. Ran), pp. 89–138, Oper. Theory Adv. Appl. OT 122, Birkhäuser Verlag, Basel, 2001.

    Google Scholar 

  30. J.A. Ball and V. Vinnikov, Zero-pole interpolation for meromorphic matrix functions on an algebraic curve and transfer functions for 2D systems, Acta Appl. Math. 45 (1996) no. 3, 239–316.

    Article  MathSciNet  MATH  Google Scholar 

  31. J.A. Ball and V. Vinnikov, Zero-pole interpolation for matrix meromorphic functions on a compact Riemann surface and a matrix Fay trisecant identity, Amer. J. Math. 121 (1999) no. 4, 841–888.

    Article  MathSciNet  MATH  Google Scholar 

  32. J.A. Ball and V. Vinnikov, Overdetermined multidimensional systems: state space and frequency domain methods, in Mathematical systems theory in biology, communications,computation, and finance (eds. J. Rosenthal and D.S. Gilliam), pp. 63–119, IMA Vol. Math. Appl. 134, Springer, New York, 2003.

    Google Scholar 

  33. J.A. Ball and V. Vinnikov, Lax-Phillips scattering and conservative linear systems: A Cuntz-algebra multidimensional setting, Memoirs of the American Mathematical Society, 178 no. 837, American Mathematical Society, Providence, 2005.

    Google Scholar 

  34. H. Bart, I. Gohberg, and M.A. Kaashoek, Minimal factorization of matrix and Operator functions, Oper. Theory Adv. Appl. OT 1, Birkhäuser Verlag, 1979.

    Google Scholar 

  35. H. Bart, I. Gohberg, M.A. Kaashoek, and A.C.M. Ran, Factorization of matrix and operator functions: the state space method, Oper. Theory Adv. Appl. OT 178, Birkhäuser Verlag, Basel, 2008.

    Google Scholar 

  36. H. Bart, I. Gohberg, M.A. Kaashoek, and A.C.M. Ran, A state space approach to canonical factorization with applications, Oper. Theory Adv. Appl. OT 200, Birkhäuser Verlag, Basel, 2010.

    Google Scholar 

  37. V. Belevitch, Classical Network Theory, Holden-Day, San Francisco, 1968.

    Google Scholar 

  38. T. Bhattacharyya, J. Eschmeier and J. Sarkar, Characteristic function of a pure commuting contractive tuple, Integral Equations Operator Theory 53 (2005), no. 1, 23–32.

    Article  MathSciNet  MATH  Google Scholar 

  39. T. Bhattacharyya, J. Eschmeier and J. Sarkar, On c.n.c. commuting contractive tuples, Proc. Indian Acad. Sci. Math. Sci. 116 (2006), no. 3, 299–316.

    Google Scholar 

  40. L. de Branges, Factorization and invariant subspaces, J. Math. Anal. Appl. 29 (1970), 163–200.

    Article  MathSciNet  Google Scholar 

  41. L. de Branges and J. Rovnyak, Canonical models in quantum scattering theory, in: Perturbation Theory and its Applications in Quantum Mechanics (C. Wilcox, ed.) pp. 295–392, Holt, Rinehart and Winston, New York, 1966.

    Google Scholar 

  42. L. de Branges and J. Rovnyak, Square summable power series, Holt, Rinehart and Winston, New York, 1966.

    Google Scholar 

  43. V. Brodskiĭ, I. Gohberg, and M.G. Kreĭn, The characteristic function of an invertible operator, Acta Sci. Math. (Szeged) 32 (1971), 141–164.

    Google Scholar 

  44. J. Eschmeier and M. Putinar, Spherical contractions and interpolation problems on the unit ball, J. Reine Angew. Math. 542 (2002), 219–236.

    Article  MathSciNet  MATH  Google Scholar 

  45. C. FoiaŞ, A. Frazho, I. Gohberg and M.A. Kaashoek, Metric Constrained Interpolation, Commutant Lifting and Systems, Oper. Theory Adv. Appl. OT 100, Birkhäuser Verlag, Boston-Basel, 1998.

    Google Scholar 

  46. A.M. Gleason, Finitely generated ideals in Banach algebras, J. Math. Mech., 13 (1964), 125–132.

    MathSciNet  MATH  Google Scholar 

  47. I. Gohberg and M.A. Kaashoek (eds.), Constructive Methods of Wiener-Hopf Factorization, Oper. Theory Adv. Appl. OT 21, Birkhäuser Verlag, Basel, 1986.

    Google Scholar 

  48. I. Gohberg, P. Lancaster, and L. Rodman, Matrix polynomials, Academic Press, New York, 1982.

    Google Scholar 

  49. A Grinshpan, D.S. Kaliuzhnyi-Verbovetskyi, V. Vinnikov, and H.J. Woerdeman, Classes of tuples of commuting contractions satisfying the multivariable von Neumann inequality, J. Funct. Anal. 256 (2009), no. 9, 3035–3054.

    Google Scholar 

  50. J.W. Helton, S. McCullough and V. Vinnikov, Noncommutative convexity arises from linear matrix inequalities, J. Functional Analysis 240 (2006) no. 1, 105–191.

    Article  MathSciNet  MATH  Google Scholar 

  51. R.E. Kalman, Mathematical description of linear dynamical systems, J. SIAM Control Ser. A 1 (1963), 152–192.

    MathSciNet  MATH  Google Scholar 

  52. R.E. Kalman, P.L. Falb, and M.A. Arbib, Topics in mathematical system theory, McGraw-Hill, New York, 1969.

    Google Scholar 

  53. P.D. Lax and R.S. Phillips, Scattering Theory, Pure and Applied Math. 26, Academic Press, Boston, 1989.

    Google Scholar 

  54. M.S. Livšic, On a class of linear operators in Hilbert space, Mat. Sbornik N.S. 19(61) (1946), 239–262; English translation: Amer. Math. Soc. Transl. (2) 13 (1960), 61–83.

    Google Scholar 

  55. M.S. Livšic, Operators, oscillations, waves (Open Systems), Translations of Mathematical Monographs 34, Amer. Math. Soc., Providence, 1973.

    Google Scholar 

  56. P.S. Muhly and B. Solel, Hardy algebras, W * correspondences and interpolation theory, Math. Ann. 330 (2004), no. 2, 353–415.

    Article  MathSciNet  MATH  Google Scholar 

  57. P.S. Muhly and B. Solel, Canonical models for representations of Hardy algebras, Integral Equations Operator Theory, 53 (2005), no. 3, 411–452.

    Article  MathSciNet  MATH  Google Scholar 

  58. B. Sz.-Nagy and C. Foias, Harmonic analysis of operators on Hilbert space, North- Holland/American Elsevier, 1970; revised edition: B. Sz.-Nagy, C. Foias, H. Bercovici, and L. Kerchy, Harmonic analysis of operators on Hilbert space. Second edition. Revised and enlarged edition., Universitext, Springer, New York, 2010.

    Google Scholar 

  59. G. Popescu, Characteristic functions for infinite sequences of noncommuting operators, J. Operator Theory 22 (1989), 51–71.

    MathSciNet  MATH  Google Scholar 

  60. G. Popescu, von Neumann inequality for (B()n)1, Math. Scand. 68 (1991), 292–304.

    MathSciNet  MATH  Google Scholar 

  61. G. Popescu, Multi-analytic operators on Fock spaces, Math. Ann. 303 (1995), 31–46.

    Article  MathSciNet  MATH  Google Scholar 

  62. D. Sarason, Sub-Hardy Hilbert Spaces in the Unit Disk, John Wiley and Sons Inc., New York, 1994.

    Google Scholar 

  63. J.C. Willems, Dissipative dynamical systems I: general theory, Arch. Rational Mech. Anal. 45 (1972), 321–351.

    Article  MathSciNet  MATH  Google Scholar 

  64. J.C. Willems, Dissipative dynamical systems II: Linear systems with quadratic supply rates, Arch. Rational Mech. Anal. 45 (1972), 352–393.

    Article  MathSciNet  MATH  Google Scholar 

  65. M.R. Wohlers, Lumped and distributed passive networks: a generalized and advanced viewpoint, Academic Press, New York, 1969.

    Google Scholar 

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Ball, J.A., Bolotnikov, V. (2012). Canonical Transfer-function Realization for Schur-Agler-class Functions of the Polydisk. In: Dym, H., Kaashoek, M., Lancaster, P., Langer, H., Lerer, L. (eds) A Panorama of Modern Operator Theory and Related Topics. Operator Theory: Advances and Applications(), vol 218. Springer, Basel. https://doi.org/10.1007/978-3-0348-0221-5_4

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